Sometimes you need a new thermostat for your home's HVAC system. Here's the list of five thermostat-busting problems that require a thermostat replacement.


1. Your Thermostat Is Damaged

Thermostats are damaged by a number of destructive forces. Flood waters and high humidity corrode the components of thermostats. Fire and smoke damage controls, sensors, and displays. Rats and rodents chew wires and cause electrical shorts and other problems. Blunt-force trauma can break the face or mechanical parts of thermostats.


If your thermostat is seriously damaged, it must be replaced with a new model. A broken or compromised thermostat can cause serious problems with your home's wiring and your HVAC unit.


2. You Replace the Furnace or AC Unit

When your HVAC professionals install a new furnace or AC unit, have your thermostat upgraded too. In some cases, you'll need a fresh, updated thermostat to handle a more energy-efficient HVAC unit.


There are three different types of thermostats in use in most of the US. The type of thermostat you need depends on the type of system you have.

The three types of thermostats are:

  1. Low-voltage
  2. Line-voltage
  3. Millivolt

Low-voltage thermostats are used most often with conventional forced-air furnaces using gas or electric heat. They're also commonly used with heat pumps, boilers, and electric AC systems. Low-voltage thermostats are acceptable for use with single-stage and multiple-stage HVAC appliances.


Line-voltage thermostats control baseboard heaters, wall heaters, and heating systems in individual rooms. They’re also used to regulate temperatures when you use oil-fired boilers with baseboards and radiant heating systems.


Millivolt thermostats are self-powered and not used for most residential applications. The millivolt system is used with gravity-wall heating systems, top-vent heating systems, and direct-vent heating systems used in manufactured housing.


3. Your Present Thermostat and HVAC System Are Mismatched

Dirty air filters, improper settings, and loose connections can cause your heating and cooling system to perform poorly. When you've checked out all of the possible problems, yet your HVAC system is still not responding, you may have a mismatch of your HVAC system and your thermostat.


A contractor in the past may have installed a new furnace without replacing the old thermostat. A DIYer may have installed the wrong thermostat on the home's HVAC setup. Whatever the reason for the mismatch, the problem must be addressed.


HVAC professionals must take apart your thermostat to check the wiring of the system. That's the only way to know for sure that the HVAC system and the thermostat are not compatible. After your new thermostat is installed, your furnace and AC units will run properly.


4. The Thermostat Is in the Wrong Place

If your HVAC system isn't heating or cooling rooms as much as you think it should, your thermostat may be sending the wrong signals to your furnace or AC unit. At the same time, your thermostat may be in perfect working order. The problem isn't with the mechanics or settings of the thermostat in some cases.


The problem may be caused by the location of your thermostat. If direct sunlight warms up the sensors of your thermostat, the thermostat will think everything is within the set range. There's no way for the thermostat to let the furnace know that the rest of the house is freezing cold.


Likewise, if the thermostat is located next to a drafty spot, it may tell the furnace to kick on more often than is needed for household comfort. The same problem may occur with your AC unit if the thermostat is located near a stove in your home.


Have your HVAC tech move the thermostat to a location that reflects the temperatures in the main living area of the house. Your heating and air conditioning specialist knows the best spots for the thermostat relocation.


Sometimes, small children and pets can access the thermostat — with less-than-happy results for the home climate and the power bills. Instead of moving the thermostat, have your HVAC repair company install a locking cover for your thermostat. The safe, see-through covers are a cheaper option than removing and rewiring the thermostat in a new location.


5. The Thermostat Is Old

When your thermostat reaches the 35-year mark, it's time to have it replaced with a newer unit. Modern digital thermostats are more reliable than old units. Manual units in older houses operate with mercury-filled tubes, so your HVAC technicians will take extra care when disposing of an older thermostat.


Digital thermostats provide many benefits. For example, they:

  • Keep temperatures within a comfortable range
  • Are compatible with split systems
  • Are programmable for optimum efficiency


Some versions of digital thermostats are compatible with smart home systems. With a thermostat hooked up to a whole-home smart system, you can use your phone, laptop, or other device to change the thermostat setting whenever you like. Set the thermostat to be toasty warm or refreshingly cool as soon as you or the kids walk through the front door.


Schedule an inspection of your thermostat and your entire HVAC system by calling Henry's Service All today. We keep families comfortable year-round by delivering reliable heating and air conditioning services throughout Irving and the Dallas–Fort Worth Metroplex.