How To Repair The Pressure Switch In Your Furnace

The pressure switch in your furnace is what allows the furnace to ignite. If the pressure switch is not functioning properly, then there is no way that you can get heat into your home. This is why it is important to test the pressure switch if you are having a problem with your furnace and figure out what other problem may be occurring. Here's how to repair your pressure switch:

Before you start, be sure that the pressure switch's power wire is disconnected from the terminals connected to the switch. 

How to Test Pressure Switch:

  • The ohm meter, located at the terminals of the pressure switch should read 0. If that reading reads a number that is infinity or higher, then that means that there is a pressure switch failure, and you will need to replace it. 
  • Another option for testing the pressure switch is using a volt-meter at the end of the terminals. The volt-meter needs to read between 24 to 28 volts in order to indicate that the pressure switch is not faulty. If the number is not in this range, then this indicates that the pressure switch will need to be replaced. 

It is important to be aware that sometimes the pressure switch actually doesn't need to be replaced if you get a bad reading when testing it. This is because it could be a cracked or broken tube that runs to the pressure switch. If this is the case, then these tubes will need to be replaced and the pressure switch tested again.

In the case of an emergency, in which you don't have the tools to test the pressure switch or the resources to replace it at the moment, then you can rely on these few tips that could potentially get the pressure switch to work to bring heat to your home:

  • Flick the pressure switch hard with your finger. 
  • If the flick with your finger doesn't work then you can disconnect the tube at the opposite end of the switch and blow softly into it until you hear something move inside of the switch, which can ignite it. 

If any of these emergency tips work, then you can easily get heat into your home for the time being. However, it is still important that you also replace the pressure switch as soon as possible to prevent further complications with the furnace down the road. Contact an HVAC company like United Heating Cooling and Plumbing Inc to replace the switch or if you require assistance diagnosing the problem with your switch.