Forum Discussion
wa8yxm
Mar 30, 2016Explorer III
On SOME Atwood and Suburan water heaters both there are parts in common
On others, not so.
On most modern Atwood the thermostats and control board are common.. But again, not all.
If yours is like mine (Control and T-Stats are common) then the following furnace tribble shooting guide may help.. I'm told I did not miss much when I created it,, Ignore all references to time delays save for the 3 second one, Blower and sail switch, and cool down periods.
When the T-Stat calls for heat the control board starts the blower (1)
The blower blows closing the sail switch (2)
The control board then opens the gas valve (3) and begins sparking (4.1)
Gas Flows (5) And ignitets (4.2)
The flame heats the flame sensor (5)
The flame sensor sends .480 volts to the control board (6)
which then detects the .480 and continues operation (*)
When the T-stat says "Enough already" (RV is now warm)
The control board shuts off the gas flow (*)
and then turns off the blower after a cool down (*)
*: At nearly every step the control board is involved. IF IT IS BAD, things will not work.. I recommend replacement boards from Dinosaur boards.. When Mine went out the Dino board was less than half the price and when opened the box the quality of construction and workmanship, and then design was very clear to my trained eyes.
1: No 12 volt to furnace, blower motor shot
2: Low 12 volt, air ducts clogged, blower "obstructed" bad sail switch
3: Bad solenoid, Clogged Gas Jet
4: .1: Bad ignition circuit (high voltage) on control board. .2: Points too wide (Very common it seems)
5: These do not often fail but they can
5: Bad connection, NOTE:
5 and * Bad wire.
* applies to all steps by the way So does bad wire/connection.
On mine, it was the control board (both furnace and water heater) Easily replaced. One screw, and some you can not go wrong electrical connections.
On others, not so.
On most modern Atwood the thermostats and control board are common.. But again, not all.
If yours is like mine (Control and T-Stats are common) then the following furnace tribble shooting guide may help.. I'm told I did not miss much when I created it,, Ignore all references to time delays save for the 3 second one, Blower and sail switch, and cool down periods.
When the T-Stat calls for heat the control board starts the blower (1)
The blower blows closing the sail switch (2)
The control board then opens the gas valve (3) and begins sparking (4.1)
Gas Flows (5) And ignitets (4.2)
The flame heats the flame sensor (5)
The flame sensor sends .480 volts to the control board (6)
which then detects the .480 and continues operation (*)
When the T-stat says "Enough already" (RV is now warm)
The control board shuts off the gas flow (*)
and then turns off the blower after a cool down (*)
*: At nearly every step the control board is involved. IF IT IS BAD, things will not work.. I recommend replacement boards from Dinosaur boards.. When Mine went out the Dino board was less than half the price and when opened the box the quality of construction and workmanship, and then design was very clear to my trained eyes.
1: No 12 volt to furnace, blower motor shot
2: Low 12 volt, air ducts clogged, blower "obstructed" bad sail switch
3: Bad solenoid, Clogged Gas Jet
4: .1: Bad ignition circuit (high voltage) on control board. .2: Points too wide (Very common it seems)
5: These do not often fail but they can
5: Bad connection, NOTE:
5 and * Bad wire.
* applies to all steps by the way So does bad wire/connection.
On mine, it was the control board (both furnace and water heater) Easily replaced. One screw, and some you can not go wrong electrical connections.
About Technical Issues
Having RV issues? Connect with others who have been in your shoes.24,242 PostsLatest Activity: May 09, 2025