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The A/C Guy of Tampa Bay Inc. Blog

A Bad Thermostat vs. Your AC: What Can Go Wrong


When Thermostats Go Bad!

Sounds a touch dramatic, but we want to make a point about how important your home’s thermostat is for the overall operation of your HVAC system. The thermostat affects comfort, energy consumption, and the health of the AC and heater. Thermostat problems often look like other HVAC troubles, and it takes a skilled professional to make an accurate diagnosis of the malfunction and fix it. 

We’ve listed below ways a thermostat can malfunction and how it affects your house and AC (as well as the general HVAC system). 

The miscalibrated thermostat

The most common way a thermostat can “go bad” is a miscalibration. A thermostat has a temperature sensor so it detects when an AC has reached the target temperature setting and shuts it down. A thermostat can develop a miscalibration of several degrees so it either reads the house as warmer or cooler, resulting in the air conditioner staying on too long or not running long enough. When you notice the AC isn’t hitting the temperature targets you set on the thermostat, we recommend calling us to check if the thermostat needs recalibration. 

The thermostat with lost connections

The standard thermostat has a series of wires that connect to the HVAC system. One wire turns the blower on, one turns it off. Another wire turns on the compressor to start the cooling cycle, another turns it off. If a wire comes loose or frays or corrodes, the thermostat will lose one of its key functions. For example, if your AC’s compressor begins to run constantly, it may mean the wire connection to turn the compressor off has failed. Technicians can either repair or replace a thermostat that is no longer properly connected to the HVAC system.

The grimy thermostat

A thermostat can get dirty inside if it’s old enough, and this will cause a range of difficulties, such as inconsistent temperatures and the air conditioner beginning to short cycle. You don’t want to attempt to “clean” the inside of a thermostat yourself. Have professionals see what can be done. If the thermostat is old enough, replacing it may be the best solution.

The poorly matched thermostat installation

Finally, a thermostat could start out bad. Not so much that the thermostat has problems, but it was not the right installation for the HVAC system. Modern thermostats aren’t simple plug-n-play devices where you can pop out an old unit and put in a new one. Thermostats with programmable features, Wi-Fi thermostats, and smart thermostats have their own algorithms that can conflict with an already existing HVAC system and damage it. This often happens when a homeowner purchases their own thermostat (usually one found online) and tries to install it. Please, leave the job of selecting and installing a new thermostat to pros. Otherwise, you may be in for an expensive AC repair in Clearwater, FL, even a full replacement.

Call us if you think you need thermostat service to help your HVAC system. The A/C Guy of Tampa Bay Inc. serves our Tampa Bay family with integrity and honor. 

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