How Can I Make the Furnace Work if the Thermostat Is Broken?

How to Determine Whether the Thermostat Is Broken

​Your HVAC system is managed by your thermostat. Your whole-house fan, AC unit, and furnace won't operate if it's broken. Typical indicators that a thermostat is broken are:

• A thermostat display that is unresponsive
• a dimmed or lacking readout on the display
• AC or heater not working properly, even after adjustments
• Even after you've reached the ideal temperature, the air conditioner or heater remains on.
• Before you achieve the desired temperature, the heat or air conditioning switches off.
• The temperature varies across rooms.

​You can attempt some do-it-yourself fixes for your HVAC system before contacting experts. The following items may help your heater and air conditioning unit:

If the thermostat is broken, how can I get the furnace to operate

​If the home is cold but your furnace won't start, there may be a malfunctioning thermostat. When the temperature in your house drops to the desired level, the thermostat senses it and tells your furnace to turn on. If your thermostat breaks, you don't have to wait for a repairman to arrive or to go to the store to obtain a new one. If you temporarily disable the thermostat, your home will quickly become heated.

Make sure the thermostat is clean

You could see whether your thermostat needs to be cleaned if the issue isn't with the power or the batteries in the control panel. The operation of an HVAC system can be impacted by contaminants such as dust, grime, and nicotine accumulation. Certain thermostats have a rapid opening mechanism that lets you clean the interior. You would have to remove the faceplate for others. 
Use gentle instruments, such as dry, clean paintbrushes, to clean your thermostat. Additionally, you can use pressurized air to blast into the panel, but be sure to follow the can's safety precautions. Before cleaning the thermostat, take out the batteries and turn the device off.
​Now follow following steps:

Step 1:

​Switch off the furnace's circuit breaker. After finding it, turn the breaker to the "Off" position.

Step 2:

​Take off the thermostat cover in step two. Some versions have a plastic cover that can be removed, while others require you to loosen a few screws. Place the cover down.

Step 3:

​Find the white and red wires that are fastened to the thermostat's two screws. Using a screwdriver, loosen the screws and remove the wires that are wrapped around them. Don't let the cables to disappear back behind the wall; hold onto them.

Step 4:

​Join the two wires by wrapping their exposed ends together. To keep them from falling behind the wall, slide a pencil behind them.

Step 5:

​Turn the furnace breaker back to the "On" position in step five. It should light up and start heating your furnace.