Pressure switch: A quick explanation
To understand the pressure switch’s job, it helps to know how your furnace turns on:
- Your home’s temperature drops below the thermostat’s temperature setting.
- The thermostat senses this and calls for heat from the furnace.
- The furnace control board turns on the inducer blower. This blower clears out old combustion gases from the heat exchanger and pulls in combustion gases and air into the burners so they can ignite.
- When there is a correct draft pressure, the pressure switch (normally open) closes (making a click noise).
- The furnace ignition process starts and you get heat.
Now, in Ken’s case, the inducer fan was running and the pressure switch would click a few times before shutting down, signaling that there’s a problem.
Solution: Install an attenuator. Reset the system.
Kenny ended up installing an attenuator which creates back pressure to trigger the pressure switch, which in turn starts the furnace’s heating process
Then, Kenny reset/checked the system to make sure the error code was no longer showing. Finally, he ran the heat and went over the details of the repair with Ken before leaving.
Note: Keep in mind that the cost and time to fix a furnace all depends on what’s wrong with it.
There’s no one-size-fits-all approach. If your furnace is having issues, the first step is always to have a professional diagnose what’s wrong.
It’s just like how a doctor asks questions and diagnoses what’s wrong with you before recommending a course of treatment to remedy the problem.