how to figure out the best spot for thermostats?

stevo_2

How do you figure out the best spot to put thermostats? Is there a rule of thumb? What if you also have a fireplace that you use for heat?

BillW@honeywell

Stat mounting

Mount them on an interior wall at average eye level. Make sure you fill the wiring hole with insulation material or non-oil base sealer so the stat won't sense wall cavity temperature. Make sure stat is not exposed to the sun, drafts from doors or windows or heat/cold from any other source. Do not mount the stat behind furniture, draperies or doors.

Avoid high traffic areas where the stat could be damaged by people carrying material or by running into it, and keep it high enough that small children can't get at it. Use 18 gauge 4 or 5 conductor wire ONLY! If it is one of the old mechanical types it must be level. Read the instruction manual carefully, so that you can get the maximum performance from the stat, save energy, and still maintain your comfort level. Don't forget to set the heat anticipator on older models, or set the number of cycles per hour on the newer models. Refer to the manual for more details. Most electronic stats come from the factory set for 6 cycles per hour for forced air heat, and 3 cycles per hour for cooling. Older mechanical stats are set using an ammeter.

Your fireplace may cause either over heating or underheating, depending on where the stat is mounted. Traditional fireplaces draw a tremendous draft, and the stat may sense this cooler air and bring on the central heat when it is not wanted or needed. If the stat is in the same room with the fireplace, then it may sense the residual heat after the fire goes out, and may prevent the heat from coming on when needed in the rest of the house. You might have a heat-a-lator, or a fan system and that will effect stat operation too. Some thermostats offer the option of remote sensors, that allow averaging between the remote sensor(s) and the main sensor in the stat. Honeywell's PC8900 is an example. I forgot about your fireplace when I originally responded to your question.

Dale

Fireplace

Besides what Bill from Honeywell said if you use a fireplace you will trick the stat. You may want to put the stat in another room or if you have forced air heat leave the blower on when you use the fireplace to mix the heated air a bit. Thermostats can be installed in parallel as long as they're heating only, sort of like a hot water zoned house, then you can set the stat in the room with the fireplace for when you're not using the fireplace and the other stat will call for heat if the fireplace is on and the rest of the house needs heat.

stevo_2

Wow you guys are good. I am only using the stat to turn on one heater in the same room as the fireplace so I dont think it will be a problem. Thanks for your input.