โFeb-29-2016 04:01 AM
โMar-02-2016 03:51 AM
Sluggo54 wrote:That's a very good suggestion. If the "range" is set to low it could cause the cycling. That furnace should not be instantaneously cycling on and off. That could possibly make something get to hot and make the circuit breaker blow.
Some thermostats have adjustable "range" - i.e., it can be set to raise the temp 1 degree, two degrees, or three. It may be sensitive enough that a slight change in temp could cause problems. It is no cost to open it or take the cover off and find out.
โMar-01-2016 08:41 AM
โMar-01-2016 07:49 AM
โMar-01-2016 05:36 AM
โMar-01-2016 04:23 AM
liborko wrote:
Did you check burner? You have to remove valve assembly to do that. Four screws. And replace a firing electrode while it is easy.
I suspect the burner grid is rusted/gone allowing to burn too much gas triggering the limit switch. The motor starting current is very high and repeated starting might overheat the breaker.
Atwood part number for burner:#30268
Atwood part number for firing electrode:#34570
Good luck
โFeb-29-2016 08:12 PM
โFeb-29-2016 07:34 PM
โFeb-29-2016 06:35 PM
โFeb-29-2016 04:12 PM
โFeb-29-2016 03:48 PM
โFeb-29-2016 01:49 PM
โFeb-29-2016 01:43 PM
โFeb-29-2016 10:21 AM
OregonTravelers wrote:Chris Bryant wrote:
Check the current draw of the motor, then replace the breaker. Original was often a 7 amp, replacement is a 10 amp.
Don't guess that is the problem. The main furnace, the one with the problem has a 15 amp circuit breaker and the second furnace in the bedroom as a 10 amp breaker. Any other suggestions?
Carl
โFeb-29-2016 10:17 AM
โFeb-29-2016 09:40 AM
DFord wrote:
OregonTravelers, Try to figure out if the "call for heat" signal coming from the thermostat is the problem - is it continuous or intermittent.
Atwood manual for furnaces with wiring diagrams. See if you can use this manual to help troubleshoot the problem.
You could put a 12v test light in parallel with the furnace control wires and watch it to see if the on/off is being caused by the thermostat or if the thermostat call for heat is on all the time and the cycling is being done by the furnace itself.
From the wiring diagram:
There's terminal block where the 12v power enters the furnace. Terminal #1 has a red wire (12v pos), right next to that is terminal #4 has a yellow wire for 12v neg (ground). The next terminal down is #2 and it feeds the thermostat 12v pos. The thermostat signal comes back on the next terminal down (#5) on a blue wire. The diagram shows both wires for the thermostat are blue - #2 comes from the circuit breaker and #5 goes to the connection common to the sail switch and the ignition control board. The two other terminals are #3 & #6 and are not used - from the top the terminals numbers are 1-4-2-5-3-6 (confusing).
Put your test light between terminal #4 for 12v neg and terminal #5 to see when the thermostat is calling. The furnace should run continuously as long as the test light is lit. If it doesn't, then look at the sail switch and limit switch again.
In the connector on the ignition control:
The white wire on the ignition control comes from the limit switch and sail switch circuit. The blue wire is 12v pos from the thermostat. The red wire goes to the gas valve and the black wire is 12v neg. There are two red wires separately on the ignition control - one to the blower motor and one to the circuit breaker.
If the circuit breaker was killing the circuit, everything would stop at once. The blower would not finish its normal run. Look elsewhere.