I should also add I already have a new humidifier, t stat (Honeywell IAQ) and large media filter.

"he thinks the motherboard is frying the motor."

Does this mean the new motor is ruined and he has to buy a new one? I am very skeptical that a control board can ruin a motor.

My suggestion is find an new HVAC tech who can diagnose the problem before you replace your 12 year old furnace.

Yes...the new motor is fried (I saw it work, and then not work as well).

Not sure what else could cause the issue. He had 12V across the terminals for power to the motor, but the old one didn't work, and the new one stopped as well.

If I go another route for a tech, I run the risk of having to pay the ~$1500 for the motor as well, with the real risk of the motherboard really being bad.

"I am very skeptical that a control board can ruin a motor."

+1

"Do I absolutely have to replace the A/C as well, especially if the evap coil is only 3 years old?"

Think of a furnace as an air handler with a built in heat source. It gets the added cool from a completely separate A/C and the air handler's circuit board triggers the a/c under commands from the thermostat. That's three separate things working together and, with some allowances for things physically fitting within other things' sheet metal, parts is parts.

Some purists will disagree, and there are details skipped over here, but that's the general idea.

P.S.
There are a/c techies whose entire skill set is replacing parts until things work again. They give thoughtful troubleshooters a bad name. They're everywhere. You may have one.

P.S.
There are a/c techies whose entire skill set is replacing parts until things work again. They give thoughtful troubleshooters a bad name. They're everywhere. You may have one.

I can see why one might say that, but I am not sure that is the case here:

- I diagnosed the majority of the problem and narrowed it down to the motor would not start. Thankfully I have a thermostat that let's me do tests and I can directly turn the fan on, and it would not start

- I pulled the motor control board and looked for fried parts and saw absolutely nothing burned

- 12V across the power supply to the motor

- With new motor control board attached to new motor, and hooked up to furnace control board, I saw a test happen where the new motor spun.

- After watching all of this, and then watch him put it back in, I went upstairs and turned on the furnace. Blower never kicked in.

So unless he was sabotaging it while I was gone (which I guess could be true, but seems odd because he now comes from a sealed $1500 sale, to a $60 sale), something happened to the motor from the time we tested it until the next run.

Now, one thing that gives me pause is he said a couple of times during the whole process that he thinks a new furnace is smarter. But I was pretty clear that I would not want to buy it from them, because they only sell rebadged Johnson Control ones, and I would prefer to stay with Trane.

I think this tech is clueless and guessing. Again, I would want a second opinion.

If you keep following his advice, you could have paid for a new furnace rather than have a parts changer guess what's going on.

I would not be a happy camper at all.

Not sure of your exact location but I would be calling another Trane dealer or sister company AmStd dealer who had the identical furnace in their product offering.

IMO

This post was edited by tigerdunes on Tue, Nov 4, 14 at 6:27

"(thankfully, I am only out $60 for the work he did today)."

Why do you need to pay him $60? He has not fixed the furnace. It would be worth cutting your losses and paying $60 to get away from this guy.

I also don't feel you are responsible to pay the $1500 for the motor he ruined. If what he says is true (I still have my doubts) then it was his incompetence that caused the problem.

not convinced it was the motor at all...

TD

"Why do you need to pay him $60? He has not fixed the furnace. It would be worth cutting your losses and paying $60 to get away from this guy."

Paid him the $60 for the service call/diagnostics. He was here for 3 hours (including driving 30 minutes each way in the middle of it to go pick up the part), so I had no issues paying that part.

But you are right, I am getting away from this guy, as I am not sure what is deal is, but doesn't feel right.

"not convinced it was the motor at all..."

What could it have been, seriously? Motor is working one day, and then the next it won't turn on. New motor comes in, plugs it in and works the first time only.

This post was edited by aclute on Tue, Nov 4, 14 at 8:59

So I just realized that he left the new motor here last night -- didn't take it with him (and I have not paid for it).

Any recommendations on tests I can do to really ensure the motor is dead?

^Agreed. ECM motors rarely fail. The cheapo Chinese electronics are another story.

We can't diagnose from over the internet, and we also have no way of knowing whether your current tech is a good diagnostician. It kind of sounds like he is guessing, and a second opinion might be wise.

I don't see the point in replacing the furnace, even if the repair will be expensive. Once you fix the issue it will likely keep running for years and years. That's just my opinion. Some people will replace stuff at the drop of a hat but I'm a firm believer in keeping things running as long as they can and getting the maximum use from them.

If you do replace the furnace, no need to replace the A/C. Just reinstall the coil on the new furnace and you're good to go. Don't get hung up on brand, they're all built pretty much the same. The York furnaces are nice, particularly the mod and I would put them up against Trane any day. If a contractor bashes a brand or says theirs is better, ask for a technical explanation of why that is the case. If they aren't able to give one, kick them out of your house.

Does this furnace have any flashing codes? If so did the tech look up what they mean?

Did you try switching the fan to "on" at the thermostat to see if the blower would operate?

On some motors there is a starter capacitor. This is the first thing that should be checked. The control board usually has a relay. It is a mechanical device that will fail before any solid state component. This should also be checked.

Sometimes it just a loose connection. The point is a good tech will carefully diagnose the problem before buying very expensive parts that can't be returned.

As far as the the new motor working once, he may have wired the new board incorrectly and fried the electronics. We just don't know.

Does this furnace have any flashing codes? If so did the tech look up what they mean?

I did originally before I ever called them out. Was getting 4 flashes due to the high limit sensor cutting out. Temperature in the discharge was ~150 degrees. No motor running.

Did you try switching the fan to "on" at the thermostat to see if the blower would operate?

Yes, via my IAQ's installer diagnostics, did a fan test, and it would not turn on.

On some motors there is a starter capacitor. This is the first thing that should be checked. The control board usually has a relay. It is a mechanical device that will fail before any solid state component. This should also be checked.

I pulled the motor board on the old one, and so no fried parts, but did not check the capacitor. Now, the tech did look and saw no fried parts either, but didn't go past that.

Sometimes it just a loose connection. The point is a good tech will carefully diagnose the problem before buying very expensive parts that can't be returned.

He spent an hour diagnosing it before he left to get the parts. I watched him the entire time. Thankfully i am not having to pay for any of those parts now.

As far as the the new motor working once, he may have wired the new board incorrectly and fried the electronics. We just don't know.

I saw him do it the entire time. It was very simple as they were all just the normal plugs going right back into the same holes. 2 multi-strand wires coming from the board into the motor control board.

If it got fried from that, wouldn't that lend credence that the main board is bad as well?

When the heat goes out in the dead of winter, you pay anything to to the first guy who gets it running quickly. This time of year, the homeowner is in the drivers' seat. You have time for a second opinion and to get estimates on replacement in case the repair bill is indeed as high as the prices you are getting.

As for the motor failing, does the blower turn freely? A sticking rotor could overheat the older type motors and cause them to fail, not sure about the electronic motors - you would think they would have protection circuits.

First get a second opinion. Both on the problem and a price on replacement XV95 or AmStd equivalent. They are identical except for badging.

Then you have better info to make an informed decision.

Definitely, do not pay him for the replacement motor. Give it back to him and thank him for his time. Then politely send him on his way. Get off the path you are on. Nothing good will come of it.

IMO

Agree completely. I am done with him and that company.

Not paying for anything else.

I have 2 appointments today for quotes on the XV95, and will also ask about recommendations on fixing the current one.

As for the motor failing, does the blower turn freely?

Yes. You can move it with your hands without any issues.

Keep us posted.

So far you are out of pocket how much?

TD

Only out the diagnostic fee from last night.

$59.

Current quote from the current company to get me up and running is ~$2500 (motor, motor board and motherboard)

Get one or two of the quartz heaters that are on sale right now; it will buy you additional decision time.

I wouldn't make that repair if diagnosis is correct. You should be able to get an XV95 or AS equivalent for not much more than that plus you get the full 10 year warranty on parts. Should be no problem reusing existing evap coil.

BTW, I have exact same XV90 furnace. Hasn't missed a beat. Nearing 10 yr anniversary. Will pull a last PM this mth before warranty expires.

Good luck
IMO

If you get another company to diagnose the problem then please post the results. I would love to know what the problem is.

First quotes are in from a dealer that I thought sold Trane, but specialized in Lennox. However, he did say he could get me an American Standard as well.

Lennox EL296V, 90kBTU, 4Ton, $3888-$100 rebate

American Standard 95%, 100k BTU (AUH2C100A9), 4Ton for $3988

Best news is he could do it tomorrow.

Not bad, considering. Another quote coming at 2.

Any opinion on the Lennox?

Lennox not my fav HVAC brand.

The AmStd furnace quoted while 2 stg has conventional blower motor, not var speed. Pricing is ridiculous. I wouldn't have it.

IMO

it isn't? Looks to me like it is the American Standard Gold ZM line, and it says:

"Runs quietly and evenly distributes warm air to every room with its variable-speed fan motor"

Full model number: AUH2C100A9V4VB

Didn't have full model number. My bad, you are correct. This is same as XV95. Price a bit on high side. But even with your trouble, a very nice furnace. If purchasing new, that is the way I would go. Should be a relatively easy install, too.

IMO

Yeah, he even said that the price was a little higher because they don't do much business with them (but the rep use to work for them for 12 years, so he knows them well enough to get a unit).

Thanks for the insight. Will get the Trane quote at 2, and then go from there.

And it is done. Second place came out, and I was able to get the XV95 100kBTU, with an extended labor warranty to 5 years, for $4100.

Being installed tomorrow.

I appreciate everyone's help.

Somewhat high but obviously the labor warranty must be important to you. If that warranty is from the dealer, then of questionable value unless dealer is established in the market. I suggest you study and understand all exclusions.

Good Luck!

Yep -- I can still back out on the warranty ($350 deduction). I need to see the paperwork first, which they are going to send to me.

The warranty is through AIG.

Have you given up on the idea of repairing the current furnace?

Yep -- that ghost is gone.

Reason why: I am out at least $1500 for the motors if I do try to repair it, and if it really does need a new board, tack on $1000.

Plus, I need heat, like, now. Going to be down in the 30's tomorrow night, and spending another 2 days seeing if that will fix it will cause "marital strife".

I would not buy a 3rd party warranty.

TD

OMG! New furnance in for a week. Stops working this afternoon. Flashing 3 reds (pressure switch).

Tech comes out and finds no voltage going out of board to impeller motor.

Holy cow. Has to replace the board. Hopefully they have on locally tomorrow morning.

What is the world could have caused that?

Did the tech have any idea? Just curious as we have a 19 year old Trane and am looking at replacing.

On the flip-side, in a 8 year window we have had 2 garage door openers blow the motherboard, beginning to think we have an electrical issue.