Check that your thermostat has power If it’s a battery-powered unit, go ahead and change the batteries, even if it’s not dead. If it’s not a battery-powered unit, check that the circuit breaker for your thermostat hasn’t tripped. If it has, flip the switch and voilà, your thermostat and furnace should be working again.

Why is my thermostat on but no heat?

Seeing that your home thermostat says ‘heat on’ while in reality there is no heat is one of the most annoying things ever. What could possibly be wrong? The most common reasons for such a problem are a dirty filter, thermostat malfunction, pilot ignitor, wrong settings, or low battery issue.

Why is my furnace not putting out heat?





Check batteries of your thermostat and replace the drained or faulty one. Check the fan settings on your thermostat if they are set to “auto” instead of “on”. Make sure someone else has not set your thermostat to a lower temperature.

Can thermostat cause furnace not work?

One of the most common furnace problems is a malfunctioning thermostat. A sure sign your thermostat isn’t working properly is if your fan is constantly running. This will cause your thermostat battery to run, and cause your furnace to work inefficiently.

What happens if you install a thermostat wrong?

Potential consequences of improper installation could include: Electric shock. Blowing a circuit breaker. Damaging the thermostat unit, the electrical system or even the AC/furnace unit itself.

Why is my heat not kicking on?

If your furnace is not kicking on, it can be an issue with the thermostat. You should first make sure that the thermostat is switched to the heating function. Next, make sure that the temperature that you have the thermostat set on is lower than the temperature in the home.

How do I reset my furnace?





How to Reset an Electric Furnace

  1. First, turn off the power supply to the furnace by turning off the breaker in the circuit box.
  2. Locate the reset button on the furnace and press it to reset the furnace. …
  3. If the button is popped up, press it down.
  4. Return the cover to the blower compartment and turn the power on.


Why does my furnace turn on but not blowing hot air?

The Furnace Is Blowing Cold Air



First, check to make sure the thermostat is set correctly. You will want to make sure that the fan control is set to auto, and not ‘on’. If the thermostat appears set correctly, turn off your heater at the thermostat and check the filter. If the filter is dirty, replace it.

What do I do if my furnace is blowing cold air?

How To Troubleshoot Furnace Blowing Cold Air

  1. Step 1: Check Thermostat Setting. First and most importantly, make sure your thermostat is set to Heating Mode. …
  2. Step 2: Evaluate and Adjust Your Vents: …
  3. Step 3: Assess Furnace Filters and Replace Filters If They Are Dirty. …
  4. Step 4: Call An HVAC Pro.



Why is my heat blowing cold air?

A clogged filter is one of the leading reasons for a heater blowing cold air. But even if you swap the air filter with a brand new one, dirt and debris can still be found within the unit. This could eventually lead to overheating. If your furnace looks pretty dirty, call an HVAC provider for a professional clean.

What to do after replacing a thermostat?

After replacing a thermostat, the technician should ensure all air pockets are removed from the cooling system. Otherwise, the vehicle will be more likely to overheat. After replacing the thermostat, refill antifreeze. Leave the radiator cap off, and start the vehicle.

Will a thermostat work if wired wrong?



The connection of the wiring from the thermostat to the indoor unit control board could be incorrect or a wrong thermostat could be have been installed for the system. It only takes one wire that is incorrectly installed to not allow the system to work properly.

What happens if you wire a 2 wire thermostat wrong?

If you get it wrong, the heat will run continuously. Once you have them paired, attach one pair to “24VAC” (R) and the other to “Heat call” (W) on the thermostat. Doesn’t matter which one, since the thermostat just shorts them either way.

Can hear your furnace click on but it does not fire up?

If your gas furnace initiates the start cycle but does not fire up, it’s likely because of a faulty, damaged, or dirty ignitor/sensor. This is a very common furnace problem—you can try to clean the sensor and replace the ignitor.

Why is my furnace just clicking?

Your furnace is most likely making a clicking noise due to your furnace’s spark igniter trying to ignite the pilot light/burners. A repeated clicking indicates a failure/system malfunction. This problem is especially troublesome when you are not getting heat at some point during the very cold winter months.

How do you know if furnace ignitor is bad?



Your furnace won’t run: The most obvious sign that your ignitor is bad is that it won’t ignite, and this generally manifests itself in your furnace failing to run when you activate it. One word of caution, though: this can also be caused by other issues, some of which are electrical.

How much does it cost to fix a furnace ignitor?

Ignitor. Your furnace’s ignitor plays a critical part in the start-up process. As its name suggests, it ignites the gas your furnace turns to heat. The average cost to repair or replace an ignitor is $150–$300.

Where is the furnace ignitor located?

Unscrew and remove the service panel on the side of the furnace and find the ignitor. It is usually mounted on a V-shaped bracket near the gas port. The ignitor has two wires attached to the back of it and has a flat metal tip.