Can You Bypass A Pressure Switch On A Gas Furnace

Now use the ohmmeter to check whether the pressure switch is functioning properly.

Can you bypass a pressure switch on a gas furnace.

This might free the switch from sticking. Do not blow into a hose that is connected as this can damage the pressure switch. In no way do i recommend you attempt bypassing switch and should only be done by qualified technician. First turn the power of the furnace off.

With pump on should be closed allowing continuity. This would only be d. When you do this you should hear a clicking noise. Next take off one of the power hoses and blow on it.

If your lennox does not activate normally during the ignition sequence try running a quick bypass of the pressure switch to determine if it is the problem. If you are working on a 90 condensing furnace move to the condensate drain. How to jump or bypass pressure switch on a furnace. On newer furnaces on a call for heat the ifc checks the pressure switch.

Sometime the switch itself the part buried within can fail. As long as the induced draft blower runs and there isnt a blockage in the flue then you should be fine. So go ahead and put the hose back on put the access panel back on the furnace turn up the thermostat to its highest setting. The switch activates with air force pushing a plunger in the mechanism which closes the circuit.

Take off the end so you can blow through it to the pressure switch. Make sure the hose is not obstructed inside. You can however test with a continuity tester testing with pump off and then pump on. Remove the pressure switch hose s after carefully noting where it is connected if there is more than one hose remove and reinstall them one at a time.

Suck on the power hose and then check the switch again using the ohmmeter. 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. After all this the furnace should fire right back up. Honestly without seeing it in person i wouldn t be all gung ho about bypassing it.

If a pressure switch is not jumpered correctly the furnace will not turn on at all. If is in the closed position the furnace stops the sequence and goes into lockout mode until the switch is open.