Your HVAC system seems to be on the fritz, but it looks fine. It’s time for a DIY thermostat repair.

If your home isn’t heating or cooling the way it should, it might not be as big of a problem as you think. The thermostat controls the system and can malfunction for many reasons. While there’s no telling when a thermostat may have a problem or fail altogether. On average, it should last about 10 years, but can work for much longer.

Troubleshooting Your Thermostat

The first thing is to determine whether there may be a thermostat problem. Signs that it may be causing you trouble include:

• The air conditioner or heater runs constantly or won’t shut off.
• The HVAC short cycles, or goes on and off too frequently.
• Room temperature doesn’t match the thermostat setting.
• The thermostat doesn’t seem to have power.
• It doesn’t respond when you change the setting.
• Unusually high energy bills.

First, check that the unit is properly set. It’s not uncommon for a thermostat to be switched to a different mode accidentally; it should always be set to “cool” in the summer and “heat” in the winter. If you find otherwise, switch it to the proper setting.

If your AC or heater is running constantly, then look to see if the thermostat is set to “ON”. Switching it to “AUTO” resolves this. The system will then run only when the desired temperature needs to be reached.

For a thermostat that doesn’t seem to be responding, turn it up or down 5 degrees (lower in summer and higher in winter). The unit should click when you change the setting. In a few minutes, air should be blowing through the supply registers or return vents.

When You can DIY a Thermostat Repair

• Dead Batteries: Remove the thermostat panel and replace the old batteries with a new set. In digital thermostats, the batteries should be changed every year. If this resolves the problem, then no further action is needed.

• Cleaning: Mechanical thermostats have a lever and other moving parts that can be affected by dust. To dust off the mechanism and bimetallic coil, remove the cover and use a small brush or cloth (both at the low setting and again at the high setting). A can of compressed air can be helpful here too. And you can clean smaller metal contacts by sliding a piece of paper between them.

• Loose Connections: Inspect the wires to see whether they’re frayed or broken. If they seem intact, but loose, use a screwdriver to tighten the mounting screws and secure the connections. But if this doesn’t work and/or a wire seems faulty, you may need an HVAC technician or electrician.

You can even test your thermostat yourself. One way is to touch a short piece of low-voltage wire to the “R” and “W” terminal screw heads. The unit should be set to “AUTO” and “HEAT”. There should be no response, but if the heater kicks on, it’s time to replace the thermostat. The transformer connected to the thermostat can be tested as well; it may be near your heater/air conditioner or inside the furnace panel. Once you find it, use a multimeter (set to 50 VAC) to see whether current is running through the transformer (if not, this component must be replaced).

Thermostat Repair Denver?  

Contact Fix-It 24/7

DIY thermostat replacement is also possible. However, each model has its own instructions and parameters for installation. Depending on the unit, you may be better off hiring an electrician to help. At Fix-It 24/7, we provide HVAC, electrical, and plumbing services in the Denver area. Call (303) 214-0277 for prompt repairs by license