Mobil Homes & Thermostats.

[Paull]

I live in a older mobil home, 20 years old, and want to replace the thermostat. Can I use any one off the shelf or is a "special" one required like everything else in this place?

[Stormin Mormon]

Most of the trailer furnaces I've worked on use a 24 VAC power connection to the thermostat. Is the furnace heating only?

Pull the thermostat off, and see if it has two thin wires to it, probably red and white. If so, you most likely have a 24 VAC system.

Also, it's better to have the stat on an interior wall, often if the stat is on an outside wall, the cold air comes through the wall and confuses the stat. I fixed that in my last place by taking a bit of thin foam (used some from an old shoe inner sole) and cut and fit behind the stat.

[Paull]

Thanks, Yes it's a heating unit only. The thermostat has two wires going to the furnace. It's a Coleman furnace, model 7710-856. I'd like to use a ditial programmable thermostat. What exactly do I need to look for?

[SQLit]

If you have a heat pump you need a tstat for a heat pump. If you have a gas furnace and no cooling then the tstat is fairly inexpensive. Just check to see on the package that the unit does what you need. Match the colors and your done. Does not hurt to unplug the furnace if you not familiar with the electrical part 24 v does not hurt but you could short out the transformer and that would be bad.

[LornePost]

I'm waiting for an answer as well. I just bought the old style round Honeywell manual to replace my original Coleman thermostat now I'm not sure if it is right. My old one started requiring huge adjustments to just change the temp a few degrees. I suspect there is an adjustment that can be done to the little pointer arrow inside to fix this but I don't know how to do it so I decided to replace it.

[yar]

On Fri, 06 Feb 2004 20:46:26 GMT, [e-mail] blurted forth:

"On Fri, 6 Feb 2004 19:51:51 GMT, "Paull" wrote: " ">

">On 6-Feb-2004, "Stormin Mormon" wrote: ">

">> Most of the trailer furnaces I've worked on use a 24 VAC power connection ">> to ">> the thermostat. Is the furnace heating only? ">>

">> Pull the thermostat off, and see if it has two thin wires to it, probably ">> red and white. If so, you most likely have a 24 VAC system. ">>

">> Also, it's better to have the stat on an interior wall, often if the stat ">> is ">> on an outside wall, the cold air comes through the wall and confuses the ">> stat. I fixed that in my last place by taking a bit of thin foam (used ">> some ">> from an old shoe inner sole) and cut and fit behind the stat. ">

">Thanks, ">Yes it's a heating unit only. The thermostat has two wires going to the ">furnace. It's a Coleman furnace, model 7710-856. I'd like to use a ">ditial programmable thermostat. What exactly do I need to look for? " "I'm waiting for an answer as well. "I just bought the old style round Honeywell manual to replace my original "Coleman thermostat now I'm not sure if it is right. "My old one started requiring huge adjustments to just change the temp a few "degrees. "I suspect there is an adjustment that can be done to the little pointer arrow "inside to fix this but I don't know how to do it so I decided to replace it.

i would like to know also i have a 20 year old mobile with an air conditioner /heat pump and would,like to get a programable type thermostat that you can set it for one temp over night and just before i get up it would auto matically bring the temp up for and hour.

------------------------- Remove NO SPAM to Reply! Add yar where NO SPAM was!

[Stormin Mormon]

Sounds like a 24 volt system to me. I'm not really familiar with all the different types of thermostats, I went to my heating supply and got what they said worked well.

As for the round Honeywell, they need to be level in order to work right. When you take the old therm off the wall, the new "round" comes apart. the sub base mounts iwth a couple screws. There is a flat spot on top of the sub base, and you need to use a bubble level to make sure it goes onto the wall level. Should say all that in the manual that came with the therm.

[Stormin Mormon]

We have very few heat pumps in my part of the world, and I've got no experience with them. Wish I was more help.

[CBhvac]

Ok..you have a 95,000BTU in, 75,0000 BTU output gas fired furnace. It IS a 24VAC powered unit, (transformer) and you can use pretty much any stat you want. You state that you have heating only...no AC at all hooked to this unit? Then, at your stat, you will have probably only two wires, and you can count out a programmable stat, unless you are willing to pull a new thermostat wire to run one....OR, you can get a battery powered unit, and ONLY battery powered unit, and thats a waste. You will be better off, perhaps moving the existing thermostat to a point closer to the return air section of the unit, and pulling a new thermostat wire, making sure you pull a C terminal...or common. I wont go into how the units wired, since altho I have a wiring diagram here, there is no telling whats been changed over the years on your unit. I will say that the R terminal, and C both come off the transformer. As a Coleman/York Dealer, I would HATE to have you wire it wrong, and then have to get a new transformer.

I suggest that you stay away from Lux, and Hunter brand stats.

[CBhvac]

Setback stats are a waste for the most part on a heat pump. 65% of what we sell are heat pumps, and I do not recommend that you use a setback stat, since the energy savings will be, minimal. Remember, with a heat pump, when you turn the stat up more than 4 degrees from set, you automatically turn on the heat strips, and you have just wasted whatever savings you had with the lower temp setting...even if you go with a digital with a wider 2nd stage band adjustment, the unit will have to run longer, to get the temp back up than a gas or oil unit, and after a set period of time, normally in the range of 10 to 15 minutes of run time, the 2nd stage will come on anyway, and then you have just ate up your savings again. With a heat pump in a mobile however, you can as well run whatever stat you want, provided that the sub-base is set up for a heat pump, and with 2nd stage heat terminals on it, since you will for SURE have electric 2nd stage. All a mobile home unit is, is an electric furnace, with a fan and defrost controller hooked to the correct stat and the heat pump. Nordyne/Intertherm uses a box that mounts on the front of the blower for this, and normally, if you have a heat pump, its been changed over to a heat pump controller. Coleman units come equipped for heat pumps, and all you have to do when installing one, is move one wire and bypass another since the controls are not hte same as a upflow, or horizontal unit..

Again...advice is the same...stay away from Hunter or Lux.

[CBhvac]

snipped garbage posting from Chris Young.

Thats called an anticipator, and its controls a small "heater" in the stat that influences it. It is to keep the unit from overshooting its set point temp. On gas and oil units, there will be a label on the gas valve, furnace ident plate, or other, that tells the anticipator setting. On heat pumps, the owners manual will tell normally, and if not..well...while there is a way, most people do not know what a 10 wrap is and how its used. The T87F you have now, (The Round One) is one of the best ones out there...provided that your anticipator is correct.

[Paull]

Thanks, great info. No, there isn't an AC on the unit. I'm using a swamp cooler. I live in New Mexico. Humidity is very low when it does exist so the cooler give me the humidity I want/need.

I'm convinced that I don't want a programmable stat now. I'll go ahead and buy a new stat. You warned against Lux & Hunter. What brand do you recommend???

Paull

[CBhvac]

terminal...or

transformer.

Ahh...excellent. I used to install MasterCools when I was in Palm Springs and the first swamps I saw were in Rio Rancho NM... Do you have the low voltage stat and control box from White Rodgers on it? I have a couple left and they are great little items. Uses a transformer like a AC unit or your furnace and a stat that resembles a normal mercury switch AC stat. The only difference is that the temp isnt listed as F, but as numbers 1-7 IIRC.. Still, allows for high and low fan control and you dont have to worry about line voltage in the stat at the wall.

Honeywell. You can get the digital non program stats for about $50...IF you want a decent one. Since its heat only, you can probably get away with a lower end Honeywell, since the programming is the same, but the controls are not as fancy.

IF you go with a standard Honeywell mercury stat, or any brand, make SURE you level it, and adjust the anticipator as stated. With digitals, you normally set the cycles per hour, and thats it. I know..not alot of information, but your instructions on the stat will tell you the proper way to set it. While most are the same, depending on teh model, it can differ.