Hello, you should simply be able to turn the thermostat to the OFF position. If you can gently pry the thermostat from its wall mounted sub base, and hold it in your hand, the back of the thermostat will have the brand name and model number. I will pull the operators manual for you.
We can go from there.
I am a retired mechanical engineer and HVAC/ electrical/ refrigeration and boiler contractor ... with 56 years in this business. The last 20 of those years consulting for major firms nationally.
All I ask is please select the***RATING LINK***at the top of your page, that is the only way I am credited through the site.
Rating does not affect your charges nor ability to refund if not satisfied.
If you need to be coached through a full diagnosis/repair, and wiring etc. for up to two days, and wish to be trained to use test instruments...... that goes well beyond' Just a simple Answer' of course.. ...rate my simple answer so far positively..and I will deliver that training and coaching to you All on the same dime so to speak.
If you can agree to that, rate now, lets continue by all means.