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How To Tell When To Replace the Thermostat

When HVAC problems arise, it’s easy and reasonable to conclude that something is wrong with the AC unit or furnace. But in many cases, the problem lies with the thermostat. Since it is essentially the control center of the entire system, a malfunctioning thermostat can cause all kinds of issues that affect the performance and efficiency of the HVAC system.

Of course, it’s not always easy to tell what might be a thermostat issue and what might be something more serious with the unit itself. So, to help homeowners troubleshoot their HVAC woes, here are three common signs that the thermostat might be failing!

Unusually High Energy Bills

One common symptom of a broken thermostat is if the energy bills are higher than normal. The HVAC system is the single biggest consumer of energy in a typical home, which makes it the most obvious culprit when there are large, unexpected spikes in energy usage. Such spikes usually result from a loss in efficiency, which a thermostat on the fritz can cause.

Suppose the thermostat isn’t reading the temperature correctly, communicating with the AC or furnace properly, or simply glitching out. In that case, it can cause the system to work harder than it should, driving up energy usage. Of course, a high energy bill may also be caused by various other issues with the HVAC system, so it’s best to have a professional inspect and test the whole system to determine whether or not the thermostat is to blame for the spike.

Inaccurate Temperature Reading

If homeowners notice HVAC issues or higher energy bills, the issue may be as simple as an incorrect temperature reading on the thermostat. Fortunately, homeowners can test this independently with tape, a paper towel/napkin, and a simple glass tube thermometer (or other small mercury thermometer). The test is as simple as this:

  • Tape the thermometer to the wall a few feet from the thermostat with a folded piece of paper towel or napkin separating the thermometer from the wall (to prevent the thermometer from picking up the wall’s heat).
  • Ensure the thermometer is roughly the same height as the thermostat and isn’t in the sun or near an air vent.
  • Wait 15-20 minutes.
  • Compare the temperatures on the thermostat and thermometer. The thermostat isn’t accurate if there’s more than a 3-degree (Fahrenheit) difference.

If the thermostat is found to be inaccurate, homeowners can try cleaning the sensors and internal components with canned air (this may require removing the thermometer face) or replacing the batteries, if applicable. If that doesn’t work, it’s time for a thermostat replacement.

The AC Is Short Cycling

Another way homeowners can tell if their thermostat might be failing is if the HVAC unit is short-cycling. This is when the system frequently turns on and off at short intervals rather than cooling or heating for full cycles (a normal cycle lasting around 10 minutes or so to maintain a set temperature, weather-depending).

One of the most common broken thermostat symptoms, short cycling prevents the home from reaching the desired temperature and puts undue stress on the AC or furnace, which can lead to much more serious issues – even a premature replacement – so it’s best to resolve the issue as quickly as possible.

Replacing a faulty thermostat is also a good opportunity to upgrade to a smart thermostat. Today’s smart thermostats come with various features designed to improve energy efficiency, enhance home comfort, and alert homeowners of potential issues with the HVAC system. So homeowners would do well to ask their trusted HVAC contractor about the possibility of installing a smart thermostat!

About Daniels Plumbing, Heating and Air Conditioning, LLC

Daniels Plumbing, Heating and Air Conditioning, LLC has been one of the most trusted and highly-rated home service companies in Santa Fe. Their trustworthy, licensed experts always arrive on time in fully stocked trucks and do the job right the first time. They offer up-front competitive pricing, 24/7 emergency service, and a 100% satisfaction guarantee on every job, so don’t hesitate to call them for thermostat replacement in Santa Fe, NM!