Help! My Thermostat Won’t Change Temperature!

Is your thermostat not allowing you to change the temperature? This issue can be linked to any of the problems covered here – your thermostat could be in locked or auto mode, it could have temperature limits set, the inside needs cleaned, or maybe it’s just broken, and it needs to be replaced.

1. Locked Mode

If your thermostat is locked then you will not have the ability to change the temperature. A lock on a thermostat does exactly that – it locks out any user trying to change the temperature set by the owner of the home.

Each brand has a different method to unlocking their thermostats so if you need to know how you should reference the owner’s manual that came with your thermostat or access it online. If you can’t find one online then you should call the manufacturer’s helpline for further assistance.

2. Auto Mode

On older thermostats, auto mode just means that the thermostat will automatically control the heating and air conditioner system to achieve and maintain the set temperature.

On some newer models, including most smart thermostats and programmable thermostats, auto-mode takes it a step further by not only automatically controlling the HVAC system but also by utilizing a set of pre-programmed temperatures set by the installer, or manufacturer.

If this is the case then you will not be able to adjust the temperature outside of the pre-programmed temperatures when the thermostat is set on auto-mode. These set temperatures can be changed within the settings of your thermostat.

3. Temperature Limits

Sometimes, in order to prevent unnecessary wear and tear on a heating and cooling system, the technician that installs the thermostat may program temperature limits to prevent the heating or cooling system in your home from being worked past its capabilities.

The method of changing the room temperature limits varies depending on the make and model of your particular thermostat- but if the limits were set by an HVAC technician then I cannot recommend you go past those set limits. This can cause expensive damage to the cold air or heating system in your home.

4. Dirty Connections

The entirety of the inside of your thermostat is made up of wires and wired connections. Regardless of how clean your home is, overtime your thermostat is going to collect dust on its inside which may interfere with the reliability of the electrical connections in your thermostat. This can lead to a host of problems, including, but not limited to, the inability to change the temperature on your thermostat, and the thermostat not reaching the set temperature.

This can be fixed by taking the cover off of your thermostat and cleaning it with a soft brush, q-tip, or a canned air cleaner. After you clean it you should make sure to tighten any loose wire connections before replacing the cover of the thermostat.

5. Broken Thermostat

Sometimes it can be hard to accept when something is broken, but if your inability to adjust the temperature cannot be attributed to any of the issues listed above, then your thermostat needs to be replaced with a new thermostat.

Thermostats are easy to replace and will wire up the same way as the one being replaced. I recommend referencing a picture of how the broken thermostat is wired and the wiring guide in the new thermostat’s installation manual.


It can be frustrating when your thermostat will not allow you to adjust the temperature of your home and it can be caused by a range of reasons – from faulty wiring and damage-preventing temperature limits to just being plain broke.

If you can’t find the problem with the list of troubleshoots above then you may need to replace the thermostat in your home altogether. If you don’t feel comfortable doing this yourself then you should contact a licensed technician in your area to address and fix the problem.