Can You Bypass Furnace Limit Switch

The function of your furnace limit switch is to tell the fan when to turn off and on depending on the temperature in the home.

Can you bypass furnace limit switch.

If a pressure switch is not jumpered correctly the furnace will not turn on at all. First turn the power off to the furnace. I am not responsible. However for your own safety don t attempt to reset the switch without first consulting your furnace s instruction manual.

How to jump or bypass pressure switch on a furnace. A 150 30 limit would open at 150 deg and reset at 120 deg. Usually limit switches are closed until the temp gets above a certain limit and then they open until it drops below a certain temp. You don t bypass a limit switch you test it to see if it is closed or open when it should be.

Depending on the furnace these two switches can be separate or together in what is called a combination switch. Some furnaces will have two or even three high limit switches wired in series and checking the temperature at different points in the furnace. How do you bypass a limit switch on a furnace. It s possible to reset the switch at home when necessary by following a few simple steps.

02 24 2012 09 56 pm 6. This would only be d. If the temperature is below the setpoint the resistance across the switchshould be zero. One way to keep your limit switch in good shape is to schedule a furnace tune up every year with jerry kelly.

If you burn your home down. If you have an ohmmeter you can measure the resistance across the switch. I have a white rodgers universal 50a55 843 with diagnostic indicator flash code 4 open high temp limit switch flashing the furnace only blows cold air. Do not bypass limit switches.

I bypassed the limit switch and the burners read more. They are there for a reason and bypassing them puts your life and home at risk. Example limit switch on amazon honeywell l4064b2236 combination fan and limit furnace control. You need a competent professional to repair this system.

There is still a lower limit switch.