Gas Furnace Pressure Switch

On newer furnaces on a call for heat the ifc checks the pressure switch.

Gas furnace pressure switch. A furnace pressure switch is a safety device located near the draft inducer motor of a gas forced air furnace. Here is a quick breakdown of the steps involved in replacing a gas furnace pressure switch once you have sourced your new part. Onetrip parts furnace pressure switch high temp tubing 3 16 i d. A pressure switch is designed to sense the negative pressure created by the draft inducer motor during the furnace startup and.

If the pressure switch is stuck it does not send enough power to the inducer and therefore the ignition sequence does not begin. The pressure switch has a pressure at which it closes which is typically negative. By this point on an 80 efficiency furnace if you haven t found the culprit you will have to put on your best thinking cap because the issue could be any number of things including a bad board loose or bad wire connections or a bad pressure switch. Lennox pressure switches and carrier pressure switches are two popular furnace pressure switch brands but it is best to purchase based on your furnace model number.

The gas valve will not open if the pressure switch doesn t work so the click sound of the gas valve opening tells us that the pressure switch is fine and the igniter is likely our problem since we should also notice it didn t try and light just prior to the click we heard. Ensure the draft is above the required pressure. A gas furnace pressure switch closes to allow current to pass through and start the ignition of the furnace. If is in the closed position the furnace stops the sequence and goes into lockout mode until the switch is open.

Example gas furnace pressure switch on amazon lefoo lf31 air furnace differential heating ventilation pressure switch 100pa before changing out an inducer motor or pressure switch keep in mind that a kinked hose clogged flue pipe or anything that stops the inducer motor from pushing air out the vent will cause a good pressure switch not to work. X 18 replaces rheem ruud weatherking 79 21491 83 4 6 out of 5 stars 125 0130f00002p goodman oem furnace replacement air pressure switch. The switch is there to prevent the furnace from running unless the correct venting air pressure is present.