Can You Bypass A Pressure Switch On A Gas Furnace

The switch activates with air force pushing a plunger in the mechanism which closes the circuit.

Can you bypass a pressure switch on a gas furnace.

Honestly without seeing it in person i wouldn t be all gung ho about bypassing it. After all this the furnace should fire right back up. Now use the ohmmeter to check whether the pressure switch is functioning properly. If you get a pressure switch code and the inducer will not come on remove one of the wires from the pressure switch.

First turn the power of the furnace off. Suck on the power hose and then check the switch again using the ohmmeter. Make sure the hose is not obstructed inside. When you do this you should hear a clicking noise.

In no way do i recommend you attempt bypassing switch and should only be done by qualified technician. The pressure switch on a lennox g16 gas furnace monitors whether the air blower is in operation. This might free the switch from sticking. 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.

How to jump or bypass pressure switch on a furnace. 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. You can however test with a continuity tester testing with pump off and then pump on. Next take off one of the power hoses and blow on it.

On newer furnaces on a call for heat the ifc checks the pressure switch. As long as the induced draft blower runs and there isnt a blockage in the flue then you should be fine. With pump on should be closed allowing continuity. Take off the end so you can blow through it to the pressure switch.

If you are working on a 90 condensing furnace move to the condensate drain. Sometime the switch itself the part buried within can fail. It doesn t take much pressure so don t blow too hard. 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.

Do not blow into a hose that is connected as this can damage the pressure switch. If a pressure switch is not jumpered correctly the furnace will not turn on at all.