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dave9733

New furnace takes 2.5 hours to warm house

David Hottman
3 years ago

We recently had a 23 year old furnace replaced with a new one. My expectation was that it would perform in a similar manner to the old one. The old one was 110,000 BTU and took 30-60 minutes to warm the house in the morning. The new 100,000 BTU furnace took 2.5 hours to heat the house this morning from 66 to 72 degrees. The new furnace has been checked multiple times and is working as specified. Is it reasonable to expect the installer to continue to try to address this until it is fixed? 2.5 hours for 6 degrees seems way too long... it was 30 degrees outside this morning.

Comments (97)

  • kevin9408
    3 years ago

    Sorry, I thought it was Saturday for some odd reason. Sucks getting old.

  • PRO
    Austin Air Companie
    3 years ago
    last modified: 3 years ago

    Is it possible for me (the homeowner) to switch out the XL 850 for something else? Like my 23 year old electronic thermostat or an ecobee? Would the relay panel need to be removed? Just curious...in case some day in the future I want to change it out.

    It will probably require new t-stat wire. As they most likely chose what they chose because communicating only requires 4 wires. The argument of higher efficient furnace for Colorado climate? I doubt it would pay you back. Colorado is a more moderate climate IMHO.

    If you attempt this before the warranty runs out, you will likely void the warranty. It's not overly complex to wire a thermostat if you know what you're doing... but because I actually do this you would be surprised how often someone makes a mess of things trying to do things they think is easy.

    Can it be done. Yes.


    There is no outdoor temperature sensor which means the thermostat is not making staging decisions on outdoor temperature.


    It's a natural gas furnace it wouldn't need or use that info anyway to make decisions for furnace operation. It's things like this that a non-professional doesn't understand.


    It's what makes you keep chasing your tail around in circles. Amusing for me of a morning while I drink my coffee. This is what I do, I actually have a reason to be here.


    I guess we'll find out if the poor guy they send out on Saturday actually deserved his title or not. If it's anything I've experienced over my HVAC career of working for others... mental abuse in exchange for no additional pay.


    If anything explains why and how I became what I am now. Sheer motivation to stop being "USED" in not so fun ways.


    ------------------

    What would take me an hour or two to fix has turned this thread into a fiasco of over 4 days now. People now claiming I am posing? My record can be easily verified thru my Youtube channel. My website(s). My Texas licensing info. etc.

    I fix air conditioners and furnaces for a living. I don't fix people or their perceptions on a forum board. You don't have to like it.

    I am not in a forum board talking about what you do for a living am I? Nope just checked it says "heating and air conditioning". Truth is stranger than fiction.

    I service the Katy, Texas area.



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  • David Hottman
    Original Author
    3 years ago

    While I am waiting for the head of installation to come this morning I read up on the specs for the CSSC connector. It specified a minimum 1.5 inch diameter bend. I happen to have some 1.5 inch disks to compare it. I tried to take a picture. The bend may be ok but it seems that a longer connector would have been a better choice to avoid a minimum diameter bend? I think I saw that a 3 inch inch is recommended? II don’t know anything about anything just looking at things.

  • David Hottman
    Original Author
    3 years ago

    The other tight bend looks better...

  • kevin9408
    3 years ago
    last modified: 3 years ago

    David, If you have concerns or even if you just want peace of mind tell the service tech to check gas pressure at the inlet and outlet of the gas valve. Page 21 of the installation manual shows the location of the 1st and 2nd stage adjustment location and the ports to attach a pressure gauge. It's a minor task and wouldn't take long and there is no reason why the tech couldn't do this in a few minutes so don't let him give a reason.

    The Minimum inlet gas pressure should be above 5 inches of water column (inches of W.C.) The 1st stage (low) should be adjusted to 1.6 inches w.c. and the 2nd stage high should be adjusted to 3.5 inches of w.c.

    Please don't attempt this yourself and let a qualified individual do this. You wouldn't necessarily hurt anything checking the pressure at the inlet or outlet port yourself with the proper gauge but could mess up things in a huge way arbitrarily turning the manifold adjustments.

  • David Hottman
    Original Author
    3 years ago

    The head of installations came today with a trainee. I asked and they checked the gas pressure. They said it was good.

    They provided me with two things this morning: 1) they lowered the 2nd stage blower speed to raise the delta temperature and 2) they told me that new furnaces are more efficient by taking longer to heat so I should expect it to take longer. They said they will call on Monday to see if it the change they made is helping.

    I am not optimistic because I think they lowered the blower speed that one of their guys raised previously. My guess the blower speed is set back to what it was originally.

    The burner flames looked good.

    It took 15 minutes to go from stage 1 to stage 2 so they want to try to lower that time. If they can I don’t see that 5-10 extra minutes of stage 2 will make much difference.

    Today was a little colder outside. Today, it took .4 hours of stage 1 and 2.4 hours of stage 2 to heat the house from 67 to 72 for a total of 2.8 hours of heating according to the thermostat.I think it was 28 outside this morning.

    I will watch it but I am not optimistic. Am I being unreasonable to want something less than an hour on a day like this?

  • Elmer J Fudd
    3 years ago
    last modified: 3 years ago

    There's something more going on. It shouldn't take so long. I'm in a milder area but even with an overnight low in the 30s, the larger part of my house (3400 sf) served by a ~90K BTU output furnace can recover a 6-7 degree nighttime setback in one hour. It's a 50 year old house, moderately insulated but far from tight.

    I'm sorry to repeat but I'd get a duct leakage test done. And maybe see if you can get another HVAC guy to look at it.

  • mike_home
    3 years ago

    You are not being unreasonable. The statement about it takes longer to raise the temperature because the furnace is more efficient is nonsense. Did he measure the gas pressure?

  • David Hottman
    Original Author
    3 years ago

    Yes he told me he measured the gas pressure. Thinking about it now I am not sure he did. I asked him him about those tight corners on the gas line. He told me there is 6-10 inches coming into the house and they only needed 1.5 and 3.5(those may be wrong), so the connection was not the problem. I think he just blew it off as a stupid question.

    Pretty much just spent a lot of time telling me that that these new furnaces are slower and I should not expect what I used to. I told him I could adjust my expectations, but not from 30-60 minutes to 2.5 to 3 hours.. he didn’t have anything to say except to give it a couple of days.

    I will check into a duck leakage test.

    He swore that the furnace is working exactly to specs but they want to make sure I am happy. Not sure what that means.

  • mike_home
    3 years ago

    Have you been able find a model number on the furnace? Maybe the wrong furnace was installed.

  • David Hottman
    Original Author
    3 years ago

    The quote I was given was for a “preferred heating system 110-120K BTU 80% 2 stage furnace with EC motor technology”. I just read the part number off of the furnace: S8X2C100M5PSABA. Not sure why that furnace instead of the size specified... I assume it was what was available?

  • kevin9408
    3 years ago

    Darn it mike, I thought of the same thing a couple hours ago and started a post but was side tracked with a lengthy phone call. Goes to show you're a thinker.

  • PRO
    Austin Air Companie
    3 years ago

    On the gas flex connector... those ribs on the wall of the tubing body prevent it from being kinked. So that is not the problem *provided of course gunk namely pipe dope, didn't some how get into it*


    Now that another check & adjustment has been performed... David Hottman, a test you can do is to find what the temperature rise is.


    The temperature rise is: Supply Temperature - Return Temperature = Temperature Rise. You need a thermometer to do this. A kitchen meat thermometer will work.


    What is the temperature rise when in 1st stage heat? 2nd stage?


    The temperature rise for most 80% natural gas furnaces will be between 30-60 degrees. This information should be listed on the data plate of the furnace. The rise number can vary due to load being put on it and the stage the furnace is in.


    If operation still not satisfactory, keep pressing the installation company.

  • David Hottman
    Original Author
    3 years ago

    I checked the temperatures this morning.. stuck my probe through tiny holes in the canvas collars in the return and above the furnace. I think the installers used the same holes. Above the furnace was 122. The return side was 75. Both measurements were on stage 2. I will look at the data plate this morning once it has warmed up the house.

  • David Hottman
    Original Author
    3 years ago

    The data plate says a range of 30-60 degrees. No separate range for stage 1 or 2.

    1.75 hours to 2.25 hours to raise the house 3 degrees this morning.

    If everything about this furnace is working good, and just looking at the end result of taking a long time to raise the temperature, is it possible that this furnace isn’t big enough? I don’t get why it wouldn’t be...where else does this lead if you assume the furnace is working per spec and everything else appeared to be working fine before the replacement?

  • PRO
    Austin Air Companie
    3 years ago
    last modified: 3 years ago

    Supply temp 122 ~ Return Temp 75 on stage 2

    75 sounds high to me for return temperature. What is the current temp at the thermostat (the temp reading not set point temp)? What temperature set point are you trying to attain (thermostat setting)?

    If you didn't take thorough notes when doing what you did... start over.

    75F is rather warm for return temp. Most people would not be trying to hit such a high temp... unless this points to?

    I service the Katy, Texas area.

  • David Hottman
    Original Author
    3 years ago

    Yea I thought 75 was wired but what do I know. The thermostat said 69 and the set point was 72. The returns come together in the ceiling of the basement and then drops to the floor to the furnace. I measured at the bottom of return and it was 85.

    I just checked again ..temp on thermostat is 72, manually turn on stage 2, top of return in basement 77 and bottom of return is 84.

    There is a humidifier on this furnace. It is attached to the duct right at the top of the furnace and it looks like it is connected to the return halfway between the ceiling and the floor. Is it putting warm air back into the furnace? My measurement for the return air temp is about 2 feet above where it enters the return.

    I attached a couple of pictures... not sure they help but I am measuring in the collars... return on the right.. furnace on the left. Humidifier is attached to back of furnace duct and is connected to the return.

  • mike_home
    3 years ago

    David,

    I would measure the temperature of the returns and supplies in the house. I would expect the returns to be at room temperature. Each supply vent is going to be different due to the length of the run. It is the temperature of the air coming out of each supply vent that matters.

  • David Hottman
    Original Author
    3 years ago

    I started thinking about how a manufacturer might specify the delta T for a furnace. Wouldn’t the manufacturer specify it as the difference between the point at where the air enters the furnace to where it exits the furnace? Wouldn’t you measure the return temperature right where it enters the furnace? Not someplace else further upstream?

    In my case, with the mixing of heated air from the humidifier raising the return temperature, isn’t the best place to measure the return temperature right where it enters the furnace? Not before it is heated by the air from the humidifier?

    I am sure I don’t know what I am talking about but would the delta T on this furnace be 122 minus the humidifier heated 84 or 85 (38 or 37) and not 122 minus 77 or 75(45 or 47)? Or is this accounted for in some other manner?

  • PRO
    Austin Air Companie
    3 years ago
    last modified: 3 years ago

    David Hottman, it's actually good you measured the temp where you did. Because had you taken the temp from the room where the filter is you may have not stumbled onto part of the problem.

    What's the problem? Elevated heat where there shouldn't be any.

    Humidifier? Is to add moisture to the air which give a feeling of warmer air only because you are adding moisture to it, not heat. The only thing I would avoid is putting the temp probe near it because it might get wet and that might influence the reading in a negative way.

    Humidity in the air has no effect on dry bulb temperature. HVAC is partly a 'feeling'. Higher humidity will make you 'feel' warmer at a lower temp. Humidity runs independent from temperature.

    Note: if your feelings are hurt you need a shrink, not HVAC LOL.

    Kidding aside.... what does this elevated return temp do to the temperature rise of the furnace?

    If right before you go into the blower compartment of the furnace (return area where the blower is pulling air back not blowing air out) the temp is 84 ---- the temp rise is off too.

    This elevated heat is more than room temp of 69. So this is the start to getting to part of the problem. Need to find out where, why, how that return temp is elevated. It should be very close to whatever the room temp is.

    Once you resolve the elevated return temp problem, retake the readings again. What is the temp rise... again. (If I were you I would call the installers back and make them do it, you paid for a working furnace... clearly It ain't working.)

    The head installer got some splaining to do now. You've got ammo, use it.

    If you've lost faith in these clowns that installed it, don't tell them what you found. Make them find it or give money back and go with a different company.


    Some people shouldn't do this for a living. This can't be understated enough. These clown shops need to be shut down.


    I service the Katy, Texas area.

  • David Hottman
    Original Author
    3 years ago

    The heated air has to be coming from the bypass humidifier. It routes a potion of the supply through the humidifier back to the return, basically preheating the return air. We have a very dry climate here. I am currently trying to keep the humidity at least 25% - 30%.

    I have been trying to find some spec for how to measure Delta T with a bypass humidifier installed. The only thing I have found so far is a discussion that you measure at the entry to the furnace and will be bumping up against the high limit switch trying to get a reasonable Delta T and needing a large CFM furnace.

    If 5 of their guys (who work and in live in this dry climate) have played with this furnace and haven’t accounted for the humidifier... I am not sure what to say...

  • PRO
    Austin Air Companie
    3 years ago
    last modified: 3 years ago

    Try and shut the humidifier off then if you think that's the case and recheck the temperature rise.

    My market really has no need for humidifiers so it's been over 20 years since I've worked around them. Things change over that amount of time.

    So shut the humidifier off and try again.


    everything I've seen on the subject of Humidifier heat gain points to 1 or 2 degree rise.

  • PRO
    Austin Air Companie
    3 years ago

    If 5 of their guys (who work and in live in this dry climate) have played with this furnace and haven’t accounted for the humidifier... I am not sure what to say...


    You'd be surprised. My experience people doing this renting, living in apartment, living with parents. HVAC is a sales based world to sell people something. At the installer level it's mostly a paycheck to paycheck type job.


    I know what I say isn't too kind. But you did just have the head of installations visit you and that took many days to occur? What does that tell you? This sort of thing gives me clues inside of a forum board. If not the humidifier / elevated return temp I can only guess where else they may have messed up.


    I am not there... this is more or less a bread crumb mission to maybe find some issues as to why it's taking so long to reach set point.

  • kevin9408
    3 years ago
    last modified: 3 years ago

    The difference between your old and new furnace is 10K Btu's and equivalent to one stove top burner turned on and isn't the problem. What may be the difference between the new and old furnace is the static pressure produced. A certain amount of pressure is required to force the air out the supply vents with enough velocity to throw and mix the heated air within the cooler air in the room and it's not happening.

    The blower speed isn't set by the return and supply temperature delta but by static pressure, and is adjusted up to the maximum static pressure specified on the Furnace data plate with little concern to the Temp delta. This is why the delta has such a wide range but I won't address the 75 degree return temp right now or any other potential "could be" problems because we're just trying to get your new furnace to work right.

    Before they removed your old furnace they should have measured the static pressure , CFM and Btu's as a reference to select a furnace. After installing the new furnace they should have set the blower speed using the reference as a guide. Factors which would determine static pressure would be Duct sizing and design so checking pressure and adjusting speed is required . Your furnace speed is adjustable from between 633 and 1691 CFM and will need to be increased up until it preforms closer to the old furnace, without exceeding the maximum static pressure stated on the furnace data plate. I think it's 0.9 in w.c. but it's on the plate. We don't know if they arbitrarily moved the speed settings without monitoring the static pressure, and because it took an hour to rise 3 degrees from 69 to 72 after you forced it into high fire (stage 2) is why I'm going this way, and it would better replicate your old furnace for comparison and what it would do from 66 to 72 in an hour. so did you see them adjust the speed monitoring the static pressure?

    Static pressure creates velocity and if it's too low the heat goes straight to the ceiling and layers in the room making the furnace run longer. Where are your return registers located; up the wall by the ceiling or low to the floor, and the same for the supply? Returns up high would explain the high return temperatures, especially with early air stratification from low velocity. Other problems would effect efficiency but would of effected the old furnace too. See if you feel a lower velocity at the supply registers if you can remember the difference.

    One problem you could address when you have time are those sloppy round duct connections seen in the 2nd picture, so Seal the connections with foil tape. If those round ducts are original to the house and installed at the same time I wonder what all the other ducts are like. Sever leakage could cause big losses and reduce velocity to the point air would barely blow out some or all supply register, something to look at. (but isn't the problem otherwise it would of effected the old furnace too.)

  • David Hottman
    Original Author
    3 years ago

    Kevin9408: thanks for the great explanation.


    "so did you see them adjust the speed monitoring the static pressure?"


    I was only here to watch the last guy, their head installer. They were in the closet and I was outside so I don't know. I couldn't hear eveything they said. I only heard discussion of temperature and adjusting the speed based on temperature. One of the previous techs said the same thing about the temp and blower speed.


    "Where are your return registers located; up the wall by the ceiling or low to the floor, and the same for the supply?"


    All returns are at floor level. 1st and 2nd floor supply registers are also in the floor. The basement registers are in the ceiling. Right now most of the basement registers are closed. The basement was only finished about 11 years ago and we mainly live on the 1st and 2nd floors.


    "One problem you could address when you have time are those sloppy round duct connections seen in the 2nd picture"


    You must be referring to where the double walled furnace and single wall water heater exhausts join together? It looks like the water heater guys (7 years ago) just pinned the outer wall of the double wall "Y" connection down to the single wall water heater exhaust pipe.


    It kind of feels like this company, that I am working with, are all doing things by rote and no one is trying to look at th bigger picture. I have a call into the owner of the business. He holds the residential heating license.


    Thanks

  • David Hottman
    Original Author
    3 years ago

    I talked to the owner of the business. He gave me the same story about how today’s furnaces take longer because they are more efficient. Not knowing what I was talking about I asked if this was an 80% 100k BTU per hour furnace? He said of course. Then I asked him... if this furnace is putting out approximately 80k BTU per hour and it is taking 2-3 times as long, it seems like I am paying 2-3 times more to get the house up to temp and how could that be more efficient. I said it seems like half the BTUs are disappearing somewhere or are not there in the first place? All I got was back was that they are more efficient so it takes longer.

    I don’t know if what I asked makes any sense in the real world but in my mind there is some kind of logic to it.

    I also told him I had a concern that his guys didn’t know how to set up a furnace with a bypass humidifier. He told you have to close the damper on the humidifier. I told him none of his guys did that. He said he would come out. Which is ok but he started our conversation by saying he spends all of his time in front of a computer any more and doesn’t get out of the office. He said he would go through and measure everything including the gas pressure... but he didn’t mention anything about static pressure. But the soonest he can get here for something like this is a week.

  • David Hottman
    Original Author
    3 years ago

    I was able to close the damper on the bypass humidifier today. The temperature before where the bypass enters the return was 72 and after was 73. The thermostat said the house temp at the time was 67. It looks like the bypass was warming the return air pretty good when it was open. The output temperature of the furnace was 117.

  • PRO
    Austin Air Companie
    3 years ago

    So 50 degree temp rise, without the humidifier. I assume this is 2nd stage heat.


    Not the best it could be, but close considering 30-60 temp rise on data plate.


    I would say run it like that as a test..... how long does it take to raise temp in the house without the humidifier? (this is only a test)


    also did they replace the humidifier when they did this job? I can't really tell by the picture you posted.


    At this point not a bad idea to involve the owner of the company.

  • mike_home
    3 years ago

    It is really disappointing when the owner of the company gives you the same illogical reason as to why it is taking 2-3 times longer to heat your house.

    Have you measured the temperature of supplies on the first and second floor? If not I would do it with the bypass opened and closed. Also do you notice any change in air velocity when opening and closing the bypass?

  • David Hottman
    Original Author
    3 years ago

    With the humidifier out of the loop it took just as long to heat the house as with the humidifier in the loop. I guess that kind of makes sense since the furnace it still operating exactly the same in both cases. The humidifier was not changed out with the new furnace.

  • PRO
    Austin Air Companie
    3 years ago
    last modified: 3 years ago

    Run a few more tests... with the home brought up to temp 72F or so. Let the furnace cycle. How long is the cycle in minutes and how many cycles per hour? a cycle starts when furnace starts up and ends with furnace reaching set point and shutting off.

    Do this with Humidifier and without. Note the outdoor temps at time of test. When running with humidifier you will need to make sure there is not a call for humidification / visually check burners of the furnace to count and time heating cycles.

    Depending on outdoor temps (load on the furnace) you should have 2 to 3 cycles per hour.

    Only 1 cycle... meaning the furnace never shuts off (can't or can barely maintain temp) points to trouble... Or the furnace relighting (short cycle).

    You will have to actually watch "babysit" the furnace for an hour for both of these tests.

  • mike_home
    2 years ago

    Did you ever measure the temperature of air coming out of the supply vents?

  • David Hottman
    Original Author
    2 years ago

    Air coming out of two of the vents was 114. I didn’t check any others.

  • David Hottman
    Original Author
    2 years ago

    I haven't been able to really watch the cycle time on the furnace because we are at the end of the heating season. The furnace is coming on to heat the house and then maybe doing a cycle or two and that is it for the day. I have tried to watch it for two days but on the second day it never cycled again. On the first day it only cycled for a little over an hour before the house got too warm.


    The one period that I was able to watch cycles started at 38 degrees outdoors and and ended at 43 degrees outdoors. all of these are Stage 1 with me watching when the burner popped on.


    9:39 AM cycled on for 3 minutes to 9:42 AM

    9:48 AM cyled on for 33 minutes to 10:21 AM

    10:26 AM cycled on for 3 minutes to 10:42 AM

    Furnace did not cycle for the rest of the day


    We have two cooler days coming up on Tuesday and Wednesday so I am going to try again then. I am curious.


  • David Hottman
    Original Author
    2 years ago

    I was able to watch the furnace cyle for two hours today with the humidifier on/damper open. The outside temperature ranged from 38 to 41 degrees. The furnace cycled on to stage one, 8 times in the two hours: 3, 5, 19, 10, 8, 7, 11, 5 minutes for an average of 8.5 minutes.


    The owner of the furance company is going to come by in the morning so I won't be able to get any cycle times tomorrow. I am not hopefulbecause it sounded like he wouldn't come out unless he could bring one of his techs. I took that as he is not comfortable with doing it himself.


    I don't know what I am doing but I did some thinking assuming CFM*Delta T*factor = BTU. I think they were measuring Delta T incorrectly because of the humidifier bypass. They used 47 degrees and I think it was 35. Using the BTU calculation (assuming CFM is constant) means that the furnace is putting out 26% less than what they think it is set for (47-35)/47 = 26%. I am probably over simplifying and missing things.


    It does not look like they measured the total static pressure of the old furnace. I found the worksheet that they used when they examined the old furance and the static pressure measurements are blank. One of the guys that did come out, must have measured static pressures later because he told me I had too much drop across the paper filter (.1) so I changed out the filter to a very thin non-paperfilter. Nothing changed when I did that a couple of weeks ago.

  • PRO
    Austin Air Companie
    2 years ago

    What you mention here doesn't sound unusual. The quote I made about typical cycles would include colder temps that would initiate 2nd stage heat as a part of that cycle. Cycling of a two stage furnace gets complicated in the term of cycling / how many cycles per hour and what those cycles consist of 1 stage or 1 & 2 stage cycles.


    So because the furnace is cycling into 1st stage a bit more frequently doesn't necessarily say anything is wrong. A 2 stage furnace will cycle a bit more. If the furnace is cycling just on 1st stage heat it is heating your home with less heat than your last single stage furnace.


    The idea in watching is knowing for a fact that it's doing what you think it's doing and not doing a lot of relighting without anyone paying attention to what it's actually doing. So that is really the point in this type of test.


    It's possible they got some settings wrong due to the humidifier heat. So it doesn't hurt to have them check things again just to be sure.


    As a side note if you like that blast of heat from traditional furnace you had before some manufacturer's allow setting to finish cycle with 2nd stage. Just be aware that this setting may over shoot your temp setting by a degree or two on occasion. (depending on load and possibly other factors)


    That setting to finish on 2nd stage doesn't really change anything when there is a real demand for 2nd stage heat. It's just an option... and due to the over shoot is the reason many don't select it because if you were to be at the thermostat seeing that your temp is off a degree or two it would generate a complaint.

  • David Hottman
    Original Author
    2 years ago

    I like the way the first stage works. It’s is quiet and keeps the house closer to the set point. One thing I wasn’t expecting is that the temperature is more uniform throughout the house as the day progresses. Something about slower for maintaining the temperature works better in this house than a stage 2 blast. That has been a good surprise.

  • mike_home
    2 years ago
    last modified: 2 years ago

    It took 15 minutes to go from stage 1 to stage 2 so they want to try to lower that time. If they can I don’t see that 5-10 extra minutes of stage 2 will make much difference.

    Today was a little colder outside. Today, it took .4 hours of stage 1 and 2.4 hours of stage 2 to heat the house from 67 to 72 for a total of 2.8 hours of heating according to the thermostat. I think it was 28 outside this morning.

    Your problem is it takes almost 3 hours to heat the house from 67 to 72 degrees. I don't see how the number of cycles to maintain the house at 72 degrees affects this problem. It is good to hear that the 2-stage furnace is keeping the temperature uniform.

    Ideally the static pressure should be 0.5 or less in the high stage, but few home duct systems can achieve that performance. I am not sure what the tech meant about measuring a 0.1 drop across the filter. Did he do measurements with and without the filter?

    The delta T at the furnace is a factor of BTU output and air flow. The BTUs of the furnace is fixed by the gas valve. You can vary the air flow to raise and lower the delta T value. You have established the delta T is within the manufacturer's range. The question is why is preventing the the temperature rise to the rest of the house. This is why I have been asking if you have checked all the supply vents for air flow and temperature.

    It is not a good sign it takes the owner of the company a week to get out from behind his desk to see why his customer is not satisfied with his new furnace. Maybe you should ask him about removing the furnace and getting a refund if he can't solve the problem.

  • Elmer J Fudd
    2 years ago

    There are clearly one or several fundamental and major problems here. Keep pushing forward and be mindful of the many good suggestions you've received in this thread. Good luck.

  • David Hottman
    Original Author
    2 years ago

    The owner of the business came by... upped the blower speed on stage 1, set stage 2 to come on only if it is over 50 outside, and told me they were here for me. I reminded him about the bypass humidifier. He said oh yea, then didn’t do anything. I asked him about stage 2. He said it was working fine without checking anything.

    I very much appreciate everyone’s assistance. It has been very helpful to me. Thank you all very much. I am leaving town for 6 weeks so I won’t be here to continue pursuing this. It will be summer when I get back so I guess I will have to wait until fall to continue to pursue. Thank you all.

  • Elmer J Fudd
    2 years ago

    That's unfortunate timing with the matter possibly unresolved. I'd let the owner know that you won't be around for follow up in the coming weeks but you hope he'll be responsive if needed in the fall.

  • PRO
    Austin Air Companie
    2 years ago
    last modified: 2 years ago

    I think the OP meant to say stage 2 when under 50 outside.

    Elmer, this is why I don't recommend going with a HVAC contractor that is always busy. Given these kinds of problems it would make you wonder if 75% of their work consists of going back over and over again. You know as in a more extreme climate. Mild climates and you never experience half the problems you do as in extreme climates.

    What is an extreme climate:

    Hot climate like mine in Katy, Texas. Hot more ways than one... humidity. The more complex a problem, the more robust the excuses have to be. I like to use examples so you see what I often talk about on this board. (for comparison purposes... you only know what you feel, see & hear. No two places are exactly alike. Different house different hurdles etc.)

    Cold Climate: Areas I've lived... Chicago area. On occasion -40 below zero wind chills.

    Colorado is more moderate. I suppose this is why this company is so slow to go back, maybe hoping the problem goes away on it's own. I also lived in Colorado, but I was real young... knee high to a grasshopper...

    Mild climate: the problems when / if they do show up... are gone 15 minutes later. (Unless of course it's a real problem that causes equipment to spit out error codes or give some sort of clues as to what may be wrong.)

    With all that said; Even living in an extreme hot humid climate... I have stumbled across equipment in which I determined after fixing it (of which was less than replacing everything--- anyone can do that) That it never worked properly since the day it was installed.

    In other words, some how, some where people just got tired and gave up the pursuit of the complaint. There's more money in purple farts and unicorn confetti. (go with a certain brand, get half a dozen quotes, pic the sub contractor installed special.) Not that this is what happened with this install... but if it did it wouldn't surprise me.

    The brand in question is American Standard. A brand often recommended on this board. Who is going to blame the brand? Yet to give you your daily dose of iron... they will blame the brand if it's anything less than American Standard, Trane, Carrier, Bryant.


    If not? what else is there?

  • mike_home
    2 years ago

    The owner of the business came by... upped the blower speed on stage 1, set stage 2 to come on only if it is over 50 outside, and told me they were here for me. I reminded him about the bypass humidifier. He said oh yea, then didn’t do anything. I asked him about stage 2. He said it was working fine without checking anything.


    Does the thermostat display an outdoor temperature? I thought you didn't have an outdoor temperature sensor. It can pick up the temperature from a local weather station through the WiFi connection.

    Changing the stage 1 speed is not going to do much for the long recovery time. Ideally the furnace should switch to stage 2 after a few minutes when it is cold outside during the recovery period. The change of having stage 2 enable only when it is over 50 degrees makes no sense. Even if stage 2 only turns on when it is below 50 degrees also is not good in my opinion. What if it is 48 degrees outside? The furnace is only going to recover using stage 1 only? This will cause a longer recovery time.

    If the owner is there for you, then have him come to your house in the fall at 7:30 in the morning and sit there watching the furnace trying to recover. The best way to trouble shoot a problem is to be there while the problem is occurring.

  • David Hottman
    Original Author
    2 years ago

    Apologies. I meant to say he set stage 2 to only come on when the outdoor temperature is under 50. He said it will use WiFi to get the local temp.

  • Elmer J Fudd
    2 years ago

    "Elmer, this is why I don't recommend going with a HVAC contractor that is always busy. Given these kinds of problems it would make you wonder if 75% of their work consists of going back over and over again."


    Name the service provider, whether a professional or a tradesman. For a non-urgent, low priority appointment. Dentist, plumber, physician, HVAC contractor, physical therapist, electrician. If they have appointments available tomorrow or the next day, I don't want one from that provider.

    Most people feel that way, emphasis on non-urgent. The best providers are busy and you have to wait for an appointment. All of my very busy providers handle urgent calls for established patients and customers immediately, there's no waiting for a response. The ones who aren't busy aren't worth using. It's an easy screen to use.

    For whatever reason, whether it's the market you're in or your position in it, you have immediate availability for non-urgent calls. And for whatever reason, you try to rationalize the situation you face compared to those with a backlog who are busier and more successful by making up imaginary scenarios to disparage them. It is what it is. People vote with their feet and their wallets and it would seem you're not getting as many votes as others get. Or, maybe the market you're in has more providers than it needs.

    The best providers in the best markets are busy and have been for a long time. They're worth waiting for.

  • PRO
    Austin Air Companie
    2 years ago

    And for whatever reason, you try to rationalize the situation you face compared to those with a backlog who are busier and more successful by making up imaginary scenarios to disparage them.


    Ok this forum board thread is imaginary. I've made this whole thread up in my head. There are others on this board. But don't worry they've all been made up by me as well.


    Define success: How many times and how long it takes you to go back. That's successful?

  • kevin9408
    2 years ago

    Maybe the busy HVAC company is staffed with incompetent hacks who can't get a job done in an efficient and timely manner plagued with problems.

    I stopped at my mother's house yesterday and noticed a HVAC van at a house next door. 30 minutes later one guy leaves the van and goes to the condensing unit. 15 minutes later another guy comes from the van and joins the first. A half hour later they were still messing around with the condensing unit and I see and hear them banging on the unit. I never had to beat on any condensing unit. Oh well, we went to lunch.

    2 1/2 hours later returning from lunch there were three additional company vans parked in front with at least 5 techs working on the condenser., well one working, the others watching but I had to leave so don't know the outcome, but they were busy, busy wasting time and company assets on one service call when the first two technicians should have been enough. It isn't hard, diagnose, replace a part or replace the condensing unit. Going with the busy company isn't a valid reason to think they're competent and is irrational, and in this case were far from efficient.

    Ray, how many employee's would you pay to watch you work if you had employees? And how many Trucks would you buy so all these guys could drive over to watch you work? Oh, they needed parts? So why didn't one guy remove the bad component and prep for replacement while the other drove to the shop or wholesale supplier for the parts? Service call comes in, oh we're sorry all your technicians are on a call right now, we can squeeze you in next week. Sure hire the busy company.

  • Elmer J Fudd
    2 years ago
    last modified: 2 years ago

    "Ok this forum board thread is imaginary."

    Not at all, OP David Hottman has an elusive and serious problem that must be resolved but I don't see any broad conclusions to be drawn. Hard to tell if his contractor is competent or not but I'd call in a different one if I were in his shoes.

    If you think his experience suggests that one-man operations in small towns who are available tomorrow are at the top of the competence and capability scale, good for you. Few will agree but have whatever opinions you want.

  • PRO
    Austin Air Companie
    2 years ago
    last modified: 2 years ago

    Ray, how many employee's would you pay to watch you work if you had employees? And how many Trucks would you buy so all these guys could drive over to watch you work? Oh, they needed parts? So why didn't one guy remove the bad component and prep for replacement while the other drove to the shop or wholesale supplier for the parts? Service call comes in, oh we're sorry all your technicians are on a call right now, we can squeeze you in next week. Sure hire the busy company.

    I couldn't have said it any better myself. What you describe is not uncommon as to what I see here.

    Mr Fudd. Trying unsuccessfully to back track now after what he said were things made up by me. When we are in a thread talking about the very reason I exist the very reason I do things the way I do.

    So Mr. Fudd you're going to call in another "busy" contractor to fix something done by another "busy" contractor? Most contractors worth anything would walk away from a new install job installed by someone else I've done it more times than I can count. They don't have a fritter to fry in such a scenario.

    Is there some HVAC company out there to help you out of a bad decision on your part? NO. Unless you get previous company to pull out equipment give money back.

    There is no warranty for improperly installed equipment. The manufacturer isn't going to help you either they will tell you to call a licensed contractor in your area.

    Why do you think it is harped over and over again by me as well as others the most important part to HVAC systems is not the brand... it's the installation and who is performing that function?

    Why do these rules even exist? primarily for more than one reason. You call in a 2nd or 3rd HVAC contractor to fix a new system. That contractor is likely to assume what when they look at the equipment serial number and see the unit is less than a year old. It would draw a flag if I looked at it being even 2 years old *IF* the house is an older house. (New construction is different)

    Why would something like that get flagged? Sales of equipment over the internet, hiring unlicensed contractors up to and including self installed or having an uncle or friend install it etc.

    So you wait 3 years then call another HVAC contractor? Maybe you fool some company doing that, but it's a fools errand.

    If you're in the Mr. Fudd camp, thinking I am just making stuff up to paint a picture?

    Truth is stranger than fiction.

    I fix air conditioners and furnaces. I don't fix people or their perceptions as to what it takes to actually do my job. You don't have to like it. Some people do, some people would rather learn the hard way. You know the imaginary made up kind of *trouble* like this thread.


    I service the Katy, Texas area.

  • Elmer J Fudd
    2 years ago
    last modified: 2 years ago

    This is as clear and cogent a comment as anything you've ever said.


    Edit to add - I was being sarcastic, I don't follow what you're trying to say.

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