Question: I am troubleshooting a furnace problem with my Atwood Hydroflame RV furnace. I have changed the Thermocoupler, and the blower relay and I am now considering the limit switch as the reason that the blower does not come on. My question is: if you shake the limit switch, should you hear a rattle?
Answer: I am not familiar enough with the operation of your specific furnace – or of the limit switch – to give you a response regarding the rattle sound.
However, I suggest you contact Atwood or the limit switch manufacturer for that information. Here is link to the Atwood website: http://www.atwoodmobile.com.
I found this on one of the forums and thought it might be of help to you:
Burner Fails to Ignite and Blower Fails to Run: Possible Causes
1)No electrical power to the furnace 2)Thermostat defective 3)Thermostat wires broken or shorted 4)Current overload protector device defective or tripped (circuit breaker) 5)Blower relay defective 6)Wire off motor 7)Wire off relay 8)Improper ground 9)Blower motor defective