Yes, unplugging the furnace will deenergize it. If the furnace has power and the red (power) and blue (common) wires touch it will blow the small fuse on the mother board. As for the plug on the furnace, I have seen furnaces wired this way. It’s in-lieu of wiring a disconnect or switch for the unit.

Do I need to turn off my furnace to replace thermostat?

Replace the thermostat if the problem remains. To replace a thermostat, first shut off the power at the service panel. Remove the cover and plate, and then label the wires with pieces of masking tape identifying their terminals.

What happens if you change thermostat without turning off power?





The short answer is no, it’s not OK – you increased your risk of electrocution and that’s never a good thing specially for a DIYer. Now that being said, everything is working and you didn’t burn down your house, so you got off OK, but generally speaking, this was a bad idea.

Does thermostat get power from furnace?

Most room thermostats on heating and cooling systems receive their 24V AC electrical power from a low voltage transformer that itself is usually found at the boiler or furnace (blue arrow in our photo at left).

Does power need to be off to install thermostat?

You do need to turn off the power when installing a Honeywell thermostat. Honeywell provides exceptional directions to assist the homeowner in the installation process. This is done to avoid injury to the person and prevent damage to the device itself.

How do I disconnect the power to my thermostat?

If this is the case with your system, it is easy to turn off the power to the thermostat. You just put off the circuit breaker marked “HVAC,” “Cooling” or “Heating.” All power to the HVAC system will be cut. This means the power of the thermostat will also be turned off automatically.

Can I replace my thermostat myself?





It is possible to save some money by installing or replacing your thermostat yourself, but you will need: Basic electrical knowledge. A general understanding of the type of equipment being used.

How do I install a new thermostat?


Quote from Youtube video: A wi-fi unit is just as easy to install. Feed the wires into the terminals. Until they click into place mount the thermostat control unit to the base by snapping it into.

How do I replace an old thermostat?

How to Replace an Analog Thermostat

  1. Step 1: Carefully Select New Thermostat. …
  2. Step 2: Shut Off Power to The Furnace. …
  3. Step 3: Remove the Faceplate From the Current Thermostat. …
  4. Step 4: Label the Wires. …
  5. Step 5: Disconnect the Wires and Remove the Wall Plate. …
  6. Step 6: Mounting the New Thermostat. …
  7. Step 7: Rewiring.

Can thermostat wires cause fire?

The safety commission reports that contact between the thermostat wires and household line voltage can damage the thermostat and cause a fire.

Is turning off the breaker the same as unplugging?



Thank you. Flipping the breaker just disconnects the power. Unplugging the unit disconnects the power, Neutral and ground. For most repairs it should not make a difference as long as you are sure that the correct breaker is flipped.

Is there a breaker on the furnace?

Your furnace would have a dedicated circuit breaker right in your panel box. A furnace usually has a double-pole breaker because of its high electricity loads, which are usually between 60 to 80 amps. So if you have a furnace and see a double-pole breaker in your panel, that’s probably it.

Can I unplug my furnace?

You can disconnect the power to the furnace by unscrewing the fuse or shutting off the switch, or both.

Where is the reset button on a furnace?



Locate the reset button on the furnace and press it to reset the furnace. It is usually located inside the blower compartment on the side of the blower motor. Be cautious as the housing may be hot. If the button is popped up, press it down.

Is AC and furnace on same breaker?

For example, if you have a furnace with an AC unit, your breaker is likely set up to both units on the same circuit. However, some homes have separate systems for each heating and cooling system. This means that their air conditioner can be powered off without affecting the furnace’s performance.

Where is the fuse in a furnace?

Quote from the video:
Quote from Youtube video: And typically that's going to be located in the lower compartment. So you have an upper compartment that has the combustion blower and burners.

Where is the HVAC breaker located?

Quote from the video:
Quote from Youtube video: You're going to have one set labeled air conditioner. This is for your outside unit. You're going to have a separate one for your inside unit which for the furnace or air handler.

Which breaker controls HVAC?



To check if this is the case, locate the A/C circuit breaker on your circuit breaker panel; it’s the main power distribution panel that can be located inside or outside of your house. It’s usually marked as “A/C,” “HVAC,” or “air-conditioner”.

Why is my furnace not blowing hot air?

Troubleshooting Furnaces Not Blowing Hot Air



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.