Thermostat war–Is your room heater fighting with your furnace? Who wins?

Perhaps the better question to ask instead of Who wins? is Who loses? You do. When the furnace and room heater are working against each other, you pay more in heating cost.

To get the furnace and room heaters to work together–and save you money–the thermostat for the furnace cannot be in the same area as the room heaters. The two thermostats will fight with each other and whichever one is set to the higher temperature wins; hint, this is usually the room heater which will cost you more money.

Room heaters may save you money if used correctly. The best use of a room heater is to increase the temperature of the rooms that you use most often to allow the furnace thermostat to be set lower, reducing how often it runs. For example, the furnace can be set to 65 degrees to keep the house at a minimum level and the room heaters can increase the temperature to 68-70 degrees for those individual rooms.  This is great in theory but will be difficult to achieve if your furnace and room heaters are not playing nice with each other.

First let’s talk about your thermostat, because that is what tells the furnace when to turn on or off based on your desired temperature. For furnaces, the thermostat is usually mounted on the wall in one of the primary rooms and can be set to a temperature, such as 68 degrees. For room heaters, the thermostat is built into the unit and may include a display for the temperature setting or simply have a dial or buttons to increase or decrease the temperature.

Scenario #1 – Your furnace thermostat is in the same room as your room heater.

You set the furnace thermostat to 65 degrees. Say you want the living room to be nice and cozy at 70 degrees so you crank up your room heater. Ahhh!  Only now the furnace temperature setting is lower than the temperature of the room and will not turn on, allowing the rest of the house to get cold. Then what happens is the heat from the warm room will carry into adjacent rooms in the house and will try to heat those rooms as well. This causes the room heaters to run more and reduces the money savings.

Scenario #2 – Your furnace thermostat is away from your room heaters.

You again set the furnace thermostat to 65 degrees and use your room heater in the living room to make that room nice and cozy at 70 degree. Because the furnace thermostat is in a separate room, not heated by the room heater, the furnace will turn on when the temperature falls below 65 degrees. The two heaters are working together, providing you with comfort and money savings.


If your scenario is similar to #1 then you may need to consider the following options.

1. Relocate the furnace thermostat to a better location that allows the room heater and the furnace to work together.

  • Keep in mind that during the summer months the furnace thermostat controls the AC and the current location may work well for cooling.
  • Moving the thermostat may leave a hole in the wall that will need repaired.
  • If moving the thermostat is not practical then consider installing a second thermostat at the desired location. The old thermostat can be abandoned or used during summer months only. (Only one thermostat can be connected to the furnace so you will need to have a qualified electrician switch the thermostat wiring at start of each season.)

2. If the room heater is only used temporarily, say only when you have company over, then you may be okay with leaving the thermostat in that room. If the rest of the house gets too cold then you could turn up the furnace thermostat until the furnace turns on and let it run for a few minutes and then turn the thermostat back down.

Note: Installing or rewiring a thermostat requires an understanding of electrical circuits and is best done by qualified electrician.

Call us at 641-437-1086; we are here to help you.


Thank You,

David McGill
James McGill


Article written by Tim McGill, editor @ Tree Branch Publishing.

save energy note

Online tips for saving energy in your home for Southern Iowa

There are many resources available on the Internet to suggest ways to save money by reducing your energy usage. However, not all online information is correct or relevant for your region. That is why I like to find information from a trusted source and one that is local.  Here are some links to resources in Iowa that are worth a look.

Iowa Energy Center

The Iowa Energy Center was created by the Iowa General Assembly and signed into law in 1990, and is administered through Iowa State University. The Energy Center’s goal is to serve Iowans through reliable, objective tools, and information. – See more at:

Recommended links:

website –

Interactive Home Energy Tour

Home Series booklets


Your Utility Company

Your utility company is often an excellent resource for energy savings tips. They also have information on rebates that may be available.

Alliant Energy (Interstate Power and Light Company)

website –

Energy Savings Calculators for residential, small business, commerical/industrial, and farm.


Charitan Valley Electric Cooperative

Newsletters – Living with Energy in Iowa

Rebate application

MidAmerican Energy

website –

Energy saving tips

Southern Iowa Electric Cooperative

website –



Your Local Contractor

Your local electrical or heating/cooling contractor is a good resource for energy savings tips. For the Centerville, Iowa area, contact McGill Repair and Construction at 641-437-1086 to discuss energy savings options for your home or business.


Thank You,

David McGill
James McGill

Article written by Tim McGill, editor@Tree Branch Publishing.


dirty vent

Keeping your vents clean makes your furnace happy

In a forced air furnace system air is circulated throughout the home by a network of tubing called air ducts. Heated or cooled air exits the air ducts into each room. This air is sometimes referred to as conditioned air–hot or cold. The unconditioned air (i.e. room temperature air or cold air) returns to the furnace via a separate network of air ducts called the cold air return.

At the air duct opening in the wall, ceiling, or floor; a vent cover, grill, or register plate generally covers the opening. Sometimes these covers will collect dirt or become blocked. This is mainly a concern with the return air vents as dust, lint, pet hair, etc. will collect on the fins as air is drawn into the air duct. vent cover

To maintain proper operation the furnace need a constant supply of return air available to the fan. If the air flow to the furnace is restricted then the efficiency is reduced and over time damage may occur.

The following are some tips to ensure good air flow:

1. The most common cause of restricted air into the furnace is a clogged air filter. Regular replacement or cleaning of your air filter is necessary. Remember, a clean air filter makes your furnace happy. For more information about maintaining your air filter, click  here.

2. Don’t block the return air vents with furniture, boxes, or other items that will prevent the air from flowing into the return air ducts. If you do have furniture in front of the return air duct then allow 4-6 inches of clearance.

3. In many homes the return air vents are centrally located in hallways or other main areas. Air is drawn from the various rooms to the central vent. When the doors to rooms are closed, air still needs to circulate back to the furnace. One simple solution is to leave a 1 inch gap at the bottom of the door.

4. Clean your vent covers periodically to remove the dust and lint which over time will build up and reduce the air flow to the furnace. We recommend using a brush attachment on your vacuum to try to keep the dirt out of the air duct. Some dirt will invariably enter the air duct during the cleaning process, so a good time to do this is just prior to replacing the air filter in the furnace.


Thank You,

David McGill
James McGill

Article written by Tim McGill, editor@Tree Branch Publishing.