Yes, you're still getting 2-stage performance with a standard thermostat. How it works is when you first need heat the furnace runs on low. If, after about 5 minutes of running in this mode, the thermostat still calls for heat, the control board automatically kicks the furnace into high stage. Most of the time the furnace runs in low mode which saves energy. You only use high stage when you turn the heat up several degrees or when it's really cold out. I actually prefer this system because standard thermostats are simpler and is one less thing to break. Be sure to add some kind of surge protection to your new furnace or that fancy control board will die an early, expensive death.

Thanks for the feedback blacknumber1. I understand that the control board in the furnace is giving some of the two stage benefits by running in low-heat and then switching to high on a timer. But it seems that the full benefits of a two stage furnace would only be realized with the proper thermostat. I guess I feel like I paid a pretty big premium to get the bells and whistles on the furnace and I want to make sure I get all of the benefits. But I certainly don't want to go to the trouble and expense of installing the 2 stage t-stat if there are no real benefits.

You are correct when you say "But it seems that the full benefits of a two stage furnace would only be realized with the proper thermostat." Maybe you need high heat a bit sooner, for shorter, or for longer? Only a 2-stage t-stat, doing what it is supposed to do, in the living area, can control your new furnace the way it was designed, and what you paid for, esp. the VS part. As a homeowner, I made sure this was covered in our new home. The board in the furnace, away from the living area, is nothing but a robot.

Are you sure there aren't enough wires there to use?

dallasbill, I am not sure how many wires are in the t-stat cable. Really I think this in a non-issue since pulling another cable would be pretty easy in my house. The installer told me that the only way he could hook-up the t-stat to operation the 2nd stage would be if I used the battery to power the t-stat continuously because there wouldn't be enough wires to run 24V power.

Honestly, I think the contractor did a real nice job on the installation overall. He had done me big favor by finishing the job a day early on a really cold night and I really didn't want to push the issue. But now I am wondering if I should call him back or just fix it myself. And would it void the warranty if I install a different t-stat?

Hello,
Many thermostat wires have extras. A typical stat REQUIRES 24 volts present at the stat to function corectly. The switch for the fan, cool, and heat is at the thermostat. It sounds like he did not have the proper stat when he did the job. If the wire can be easily replaced, I would expect the installer to replace the wire if necessary. As to the battery, it is there to maintain the digital memory in the stat only. It sounds like you have an installer that only partially installed the system. IMO the 2 stage stat is necessary when the system is a 2- stage system. I don't care if the system defaults to high heat after 10 minutes . The question is what does the contract say. If the thermostat is mentioned in the contract, then it should be assumed that it is to be upgraded for the new system.

Hi Bob, thanks for your input. The contract has a series of check boxes for what is included as part of the installation. There is a check beside the "5+2 day energystar programmable thermostat". It doesn't specifically say what model will be supplied or that it would be a 2 stage thermostat. However, since I opted for the 2 stage furnace, I assumed that the thermostat would be the right one for the job. The thermostat that was installed was a Honeywell 6000 thermostat that appears to be the 1 Heat / 1 Cool model although I have not confirmed that.

I guess I should just tell them that I am not satisfied with the arrangement and ask them to fix it. Doesn't seem like I should have to pay any extra if it is standard practice to use a 2 stage t-stat.

A 2-stage thermostat will switch back to the low stage after running at full output and the temperature is close to the setpoint. When the timer in the furnace is used, the furnace will keep running at full output (after ten minutes) until the thermostat is satisfied and the furnaces turns off.

adrianjz, are you saying that another benefit of the 2 stage T-Stat is that that there will be less temperature overshoot when High heat is needed? Interesting.

A side note, I got home this evening an found the room temperature 5 degrees below the t-stat set point. The furnace blower was on and it was blowing cold air. I put my hand on the plenum and it was stone cold too. After checking to make sure that my propane tank wasn't empty, I shut the power switch off to the furnace and then turned it back on. The furnace started right up, the burn lit and it began heating. So it seems that I'll be talking to the contractor soon anyway!

The benifits all have been discussed within the forum, and your furnace is operating at design specs. Low fire or 1)stage heating for (10)minutes and after that time if thermostat is still in a call for heat then unit switches in to high fire mode.
American Standard 90% furnace: Good model furnace
What I would ask you is that when you had your new furnace or system proposed did it include 2)stage thermosat in that proposal. If not then the contractor is NOT responsable for the price of (2) stage thermostat. If it was in your proposal then ask that one be installed..

Honeywell Pro 8000 8622 Thermostat (2) stage Thermostat

This would be my recommendation for T-stat.

Hi aircooled, thanks for your response. The proposal didn't specifically say that a 2 stage thermostat would be provided. It just said that a new programmable thermostat would be provided. There were 3 furnace options; Single Stage, Dual Stage and Dual Stage variable speed. This was for the replacement of a 16 year old (single stage) furnace. The sales/tech told me about the benefits of dual stage and variable speed. He suggested that I should only consider the upgrades if I planned to live in the house more than 5 years. I did my own research and decided that the upgrades would be worth the added cost.

I asked the sales guy a few questions regarding the existing A/C but did not discuss the thermostat. After the installation was underway (the next morning), it occurred to me to ask about the thermostat. The installer explained that he couldn't hook up the thermostat in dual stage mode because there aren't enough wires in the cable. But that the furnace timer would give the same benefits. I really didn't know if he was being 100% honest, but here is what I know now; the thermostat provided is a single stage model, there are two 4-conductor cables running to the thermostat, a 2 stage thermostat would likely perform better. As I said, I am real happy with the installation otherwise.

Thanks for the tip on the Honeywell 8000, I looked at the specs and it looks like a good choice. Actually, I think the 7 day programmable would be nice too. I will probably consider upgrading sometime in the future.

Actually, I looked at the T-Stat and found that it IS a 2 stage capable model (Honeywell TH-6220). The two T-stat cables are 5-conductor (not 4) and I would say that the installer didn't notice the 2nd cable since it is rolled up in the basement ceiling and doesn't go to the furnace. So everything that he told me hangs together and the furnace could be easily hooked up for 2 stage t-stat operation. So I feel better about what I got!

We are getting a carrier infinity 58CVA series furnace (2 stage gas valve, and variable speed) and installer furnishing vision pro 6000 thermostat with the system. Are we going to get full benefit of 2 stage gas valve and variable speed set up? Information provided by installer and internet is contradictory.

This is an 8 year old thread. Start a new one.