Can I add a thermostat to my heating system?

…and is it a good idea?

Here’s my situation: I have an approximately 2500 square foot house, 2 levels. As it’s getting a bit cold lately, I often turn on the gas fireplace at night. It puts out a LOT of heat, and the living room gets all warm and toasty. The problem with this is that the only thermostat in the house is, you guessed it, in the living room. On the weekends, when we often have the fireplace on all day, the thermostat decides that it’s 85 degrees, and there’s no need to turn the heat on.

Come time for bed, we go upstairs, open the bedroom door (it has to stay closed to keep the cats out), and it’s 30 degrees and snowing in the bedroom. OK, maybe not snowing, but you get the picture.

So is it possible to retro-fit a thermostat for the upstairs bedrooms? Does it cost a lot? Will it work? Help me!

Piece of cake. You have the right idea, and all you need to do is to get the connections right. Shut the power off to the furnace unit at the breaker, and remove the faceplate from the thermostat. Inside the thermostat, look to see which colored wires are connected where. Write it down somehow. Do the same where the wires are connected at the furnace. You probably don’t need more than one thermostat, so disconnect the wires, push them back into the wall, and then patch the wall, paint, etc. Don’t try to pull and reuse existing wire. Get appropriate thermostat wire from a home store, run the wire to the new thermostat location, connect it up at both ends and you are good to go. Turn the power back on.
Thermostats should be located where you want the temperature to be most accurate. If they are in direct sunlight, or near a heat source, they don’t really read properly and need to be moved.

Athena,

How old is your home? Even the house that my parents built in 1969 has two zones, one for each level.

I don’t know the answer but I think it would depend upon your heater.

If you can’t add another thermostat you might be able to add some baseboard type of heating system like they do for additions on homes. Other than that you might try two baby gates one on top of the other to help keep the cat out of your bedroom. To add to that get a “Skat Mat” and place it below the gates. It emits a small electrical charge where you don’t want your animal to be.

You did not mention what type of heating system you have. Forced hot air with a gas furnace is common, at least here in the midwest, so I’ll talk to that system.

A thermostat in it’s simple form is a switch that closes contacts at one temeperature and opens them at another, usually higher, temperature. It wouls be fairly simple to add a thermostat upstairs along with a switching system to select which 'stat is being used. When you go upstairs I’d imagine you’d want to switch back to the other 'stat.

The hardest part might be running the wires upstairs.

A local heating/cooling contractor should be able to help. Most thermostats are cheap so I’d guess we’re talking $150 or so.

There may be other options including relocating the existing thermostat.

It sounds like you are heating parts that don’t need it and not heating areas where you do. The thermostat should be in an area effected by that zone - and in an area you want to use as the ‘baseline’ area (or the area that ‘tells’ the thermostat when to go on and off).

But if you want to send heat to other areas of the house, while ignoring others, just relocating the theromstat won’t help. You can ajust the vents (for forced hot air) or fins (for hot water) to provide more or less heat in an area.
—or—
Also you can install a in-line fan in forced hot air systems to pump more heat to an area (and possibly hook the fan up to a 2nd thermostat to regulate it). For hot water, you must somehow break the 2 areas into seperate zones w/ it’s own thermostat. or at least set up a bypass zone.

The above is comming from a engineering background, not a plumming - while the above suggestions are possible, I don’t know if they are practial or even leagal

Just move your existing thermostat. Since you keep your bedroom door closed I’d suggest mounting it in the hall outside the bedroom.

Make sure it’s level.

Adding a second thermostat may be the way to go.

The existing thermostat is in the living room based on the assumption you spend a lot of your time in and around the living room, and so that’s where you want to be able to adjust the temperature to be comfortable.

If this is your situation, then moving the thermostat may not be the best solution. When you’re not using the fireplace, it could make it more difficult to get a comfortable temp in the main living area.

Instead, think about adding a second thermostat in parallel with the first. Put a thermostat upstairs (preferably a clock type stat, which can turn itself up & down based on the time of day, and day of the week), and set it at the lowest temp you want to maintain, say 60 degrees. And if you do use a clock thermostat, you can set it so that it only wakes up on weekends, and in the hour before you go to bed. This can save a few bucks in heating.

Since the two stats are wired parallel, either one can turn on the heat. If the downstairs stat is set at 70, but the room is 75 because of the fireplace, the upstairs stat will still turn on the heat if the temperature there drops below its setting.

On days when the fireplace is in operation, the upstairs stat will act like a low temp limit switch, keeping the furnace on just enough to keep the upstairs temp at the minimum level you set. You may even want to close the downstairs vents, since you may not need any additional heat beyond the fireplace.

On days when the fireplace is not in use, the higher setting on the downstairs stat will keep the furnace running until the downstairs is up to temp, presumably higher than the upstairs stat is set for.

Note again that since the two thermostats are in parallel, either one can turn on the heat. This means that both must be off (or set below current room air temp) before the furnace will turn off. So be careful about they are set, or you might not realize why it is warmer than you think it should be, and the furnace is still running.

But if you keep the second stat set low, this arrangement can work quite well. The second stat is fairly cheap (much cheaper than trying to zone a house that wasn’t plumbed or ducted for it), and easy to install.

Ugly

techchick: HA! Yeah, right. My “old” house was built in 1996. I bought it new. Piece o’ crap heating system… My dad is a builder, I grew up in houses that were the model of efficiency and logic. We had multiple thermostats, phone & cable jacks in every bedroom, and electrical outlets every 4’ or so. Silly me once thought all houses were built like this. Of COURSE you don’t build a 2 level 3400 square foot house with only ONE thermostat. Unless, of course, you’re a builder looking to make a buck.

Great ideas from all the other people. What I’d really like to do is put two zones in the house, upstairs and downstairs, but as I suspected it sounds like that would involve quite a bit of work. I like the idea of either moving the existing thermostat, or adding another one in parallel. That would be cool. It’s forced air heat, for those who asked. Must think about options…

In reading the other responses, I got ideas. Dangerous stuff, them ideas.

First off, if you can do the kitty-gate thing, do it. The hot air from your fireplace will eventually end up at the highest point in your home. Heat doesn’t rise, but hotter air does (in colder air). This would save you energy and let you stay reasonably comfortable. Some nice brass firedogs (with wooden lifting sticks, servants to move them, and a nice stone or concrete pad in the bedroom to put them on) would be great too.

Secondly, if you also have an air conditioning system then moving your thermostat would probably greatly increase your electric bill. You would need a second one, which could be either switched (summer downstair thermostat, winter upstairs thermostat) or in parallel.

The normal way to have two zones is to have two seperate furnace units, and two seperate sets of ducting to go along with your two thermostats. This is not an easy retrofit. You could do a two zone system with some dampers in the right place, but then you need to do something about the furnace fan to get the right airflow, and the controls would be custom rather than off the shelf. Big bucks.

Technically you “could” add another Thermostat.It would have to be wired in paralell so that either stat would operate the furnace.I’ve never seen that done,though.

Is your stat digital? Higher end digital stats have terminals to add remote sensors which will basically average
the temps together.IE your livingroom tstat reads 85…your bedroom sensor reads 60…your kitchen sensor reads 70 the thermostat will average the 3 together and “think” the house is at 71 degrees.This would “fool” your furnace into running while your fireplace is on and the livingroom hot.((keep in mind this would generally make your living room even hotter!))