Thermostat for 2 Stage gas furnace

I recently had a Lennox G61 two-stage gas forced air furnace installed. The thermostat is a regular 1 stage programmable. The furnace has a jumper on the control board to work with a one stage or two stage thermostat.

My question is, am I better off to replace the thermostat with one for two stages of heating, or leave it the way it is? My thinking is that controlling the stages from the thermostat would be the way to go. I'm not sure how the furnace decides when to turn on stage two, but I believe it is simply based on time.

I'm thinking of putting in a Honeywell 8624D instead of the stat that is there now. Is this a good choice?

Reply to
J Kelly
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WHY didn`t the installer cover this issue for you ???

WHY did you pay extra for 2 stage and not get a 2 stage stat ???

You are not telliing the whole story.

Reply to
m Ransley

Is there 4 wire or 5 wire thermostat wire run from the furnace to the tstat location?

Reply to
HeatMan

Reply to
J Kelly

Ok, I got 2 stage gas furnace but have just 1 stage thermostat. I decided not to upgrade my 1 stage thermostat as I did not see much of the benefit. From what I understand, this is how system works: Furnace is setup to work with one stage thermostat. It starts at lower output and works like that for 12 minutes. If thermostat still calls for heat, furnace switches to higher output. With 2 sttage thermostat - thermostat decides if to call for low output or high output. That is if lets say current temparature is 2 degrees from required temperature, thermostat right away will start furnace at higher output. So you are losing that lets say after setback it takes a bit longer to recover. But that is it. Is there any other advantages on having 2 stage thermostat?

Thanks

Reply to
No

For this type of furnace, I don't honestly see why you want to change the thermostat. The objective is to 'low fire' the furnace for the first 12 minutes. If that heats the residence sufficiently, then fine. Instead of firing high and using more gas, or overshooting the temperature. If the 'low fire' rate isn't getting the job done, the computer on the furnace switches to high after the 12 minute interval. So you only use the 'high' when necessary. Your using a 2 stage thermostat when the furnace manufacture provides you with a solution to use a 1 stage thermostat, and saves you from firing on the higher rate (more gas usage.) (I fully understand the 2 degree differential between 2nd stage and 1st stage.)

For my 2 cents, you have a newer 2-stage furnace is designed to work either with a 1-stage state, or 2 stage stat. It is more efficient only to use that amount of fuel that you need to keep your family comfortable. Using high fire when it's not necessary is like going as fast as you can from traffic light to traffic light, instead of just steadily getting there.

Are you seeing a need to switch to the 2 stage stat? Is the furnace getting the job done now? Is your family uncomfortable (too hot or too cold?)

Reply to
Zypher

I wasn't sure how the furnace was supposed to work. The installer said the time delay was "about 5 minutes" which seemed way to short. Therefore, I wasn't sure if a different stat would work any better (or worse for that matter). On a further note, am I weird to want an installation manual for my furnace? I did not get one, but did have one for the furnace in my last house. I know I don't need it, but I like to know as much as possible about these types of things. Maybe it would explain in better detail how the two stages sequence.

I do plan to change the stat no matter what because I do not like the one that the furnace guy installed, it does not have separate programs for each day of the week, which for me is an important feature due to my non-standard work week. I also like to have the fan on all the time when I'm home, but on auto when I'm not home. That was my main reason for liking the 8624D.

Reply to
J Kelly

Zypher you are not correct, the second stage on my unit does not require a higher blower speed there by making 2nd stage more efficient. Remember Blowers take apx 360 watts . Or 35$ at .125Kwh 24x7. An AC blower will cons`ume the same Kwh at any Btu or CFM.

2 stage is for comfort...
Reply to
m Ransley

Reply to
Shrek

This is Turtle.

Look A two stage thermostat is alway better on a two stage furnace. The next best thing is a single stag thermostat on a 2 stage furnace.

I would think it would work better and keep the air a even temp. in your home with the two stage thermostat than with the single stag thermostat.

TURTLE

Reply to
TURTLE

NEW furnace, NEW install , NEW Warranty and customer set up come to mind, or maybe THE TRUTH IS missing

Reply to
m Ransley

I had no idea he put in a one stage stat.

Reply to
J Kelly

What the f*ck are you talking about? What "truth is missing"? I guess I better add you back to the kill filter since you are obviously an idiot.

Its a new furnace installed in August of this year (in a new to me house). The dealer installed a "programmable" stat. At the time, I had no idea I needed a two stage stat so never asked about it when he installed it. He said the furnace worked on a time delay for stage two. I happened to pull the cover off and see it has a W2 terminal so thought maybe a two-stage stat would be better. So I'm looking for opinions on it.

By the way, for guys that are going to say I hired a hack, the guy came out and measured everything and did the manual j, and their service guy brought me a written bid a few days later and explained things and gave me a chance to ask any questions. I got two other estimates, one guy quoted a similar arrangement but with Heil equipment and about $1000 higher price (I got a new air conditioner also) and arrived at the proper sizes by simply looking at the house. He wrote a bid on the spot. Other one did the estimate when I wasn't there, but I've seen their installs in other houses and they did not look good. They mailed me an estimate about 10 days later.

The Lennox guy did a nice, neat job. My only complaint would be that he didn't put in the two stage thermostat and I consider it a small complaint since I would have had to pay extra for it anyway since it wasn't in the bid (or in the bid for the Heil two stage system). The thermostat they did put in was a freebie when I mentioned that I didn't care for the Hunter stat that was there already. The one the dealer gave me is a Robertshaw, so probably not a bad one, just not really what I need or want.

I'll ignore Ransley since he thinks I'm making this all up for whatever reason.

Reply to
J Kelly

Anybody with half a brain would just call the installer back

Reply to
m Ransley

You hired a hak like it or not its the wrong stat

Reply to
m Ransley

So how did the friendly competant Hack check out the furnace for proper operation after instal that is standard procedure. He didn`t, so you don`t know if the 2 stage valve works. I didnt pay till I saw everything function on my Lennox 2 stage Dimension.

Reply to
m Ransley

There is a jumper on the ShurLite board for one or two stage stat. When set to one stage, it uses time to start the second stage.

Reply to
J Kelly

As long as you realize that you will need at least 5 conductor tstat wire for the 2 stage tstat....

The Honeywell VisionPro Tstat would be a good one for this application....

Reply to
HeatMan

Jealous that I know what I'm talking about?

Reply to
HeatMan

He may have been the installer only and didn't know better.....

Reply to
HeatMan

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