In this video I explain the difference between a limit switch and a fan switch. I explain how to test them and what they do. If your furnace or heater are not turning on, this may be the problem.
Absolutely correct!! I found out when I went to buy a switch and didn't know what I was looking for. The salesman explained it to me and only then did I understand.
Fan switch N/O closes on rise, limit opens N/C opens on rise. One of the hardest concepts to get my students to understand particularly when they are both in the same unit with a spiral bi-metal.
very good thankyou very helpful so much to check for when systems don't run easily overlooked guess what if that fan got hot for a long period could ruin the limit switch it would have to be replaced if it don't go
I own an M1M series I’ve replaced the circuit board already I’m having problems with the fan not turning off after the ac/heat is done being used, only way to turn it off is to manually turn the switch off. If I turn the switch on it immediately turns the fan on without even controlling the thermostat. How do I determine if it’s the fan switch or the limit switch to be replaced?
I was told my board is bad, fan motor is bad and need to replace my thermostat. Before thermostat was not the problem but it needs to be replace. My furnace runs nonstop but blows no air. It was warm by the vent but no warm air blows. Now the serviceman wants me to buy a new furnace from them. They will not repair my furnace. Is there anymore honest serviceman around anymore???
