Furnace not working but ac is

[Bob plouhar]

No signal from ac to turn on furnace is there a fuse to check on control board ac works fine from thermostat but not furnace it is a penguin ac unit

[Bob plouhar]

Ok thank you 

[Kirk W]

There isn't usually a fuse in that circuit but it could depend upon the exact model. Dometic Penguin units have been sold for some time now and the current model is the Penguin II. Have you tested the furnace by jumpering the two blue thermostat leads to see if the furnace starts?

[dartmouth01]

There was a small fuse in my Coleman thermostat that I had to replace when I probably shorted wires when jiggling them to get the heater to work - the board was still going out and needed to be replaced, but I still needed to replace the fuse before I could get things to work.

[Wrknrvr]

  What does your thermostat look like. It is possible to reset the thermostat and it would work.

   If it is a newer model thermostat, there should be instructions to do the initiation at setup.

   That is also how to reset the thermostat.

 

   The more info we have the better we can help.

[packnrat]

yes check the two (on some only one) wire, but if you can check the thermal limiter. and if the sail switch is moving. the thermal limiter does go out. not so much on the sail.

if you sit outside with the cover off. have someone turn it on.

then keep your ears ready. you want to here sounds. (yes the blower is very noisy). you want to hear "clicking" sounds. the pizo thingy trying to light the gas.

no clicking.  pull out the burner area and check it for a broken screen, or the pizo grounding out, should be 1/8 in away from the screen.

dumb question? got gas? what color is the flame on the stove? should be blue. if other could have air (other) in the system.

find the wires to the thermal unit, check for continuity. if none... replace it as it is dead.

do you smell gas if the blower works but no heat? check for bugs, dirt, other stuff.  while the burner unit is out.

pending your heater might have to pull it out to check/change the (varied mounting locations) thermal unit. it is easier than it sounds.

these heater units are simple things. and contained in a box.

[Wrknrvr]

 There should be two blue wires from the furnace that goes to the ac control board. They are probably 18” long. So they should be easy to find.

  One of them should have 12 vdc power. If it does , just hold those two wire ends  together. The furnace should start the fan blowing. And then ignition. 

  If there is no power there. Then the furnace may not have 12vdc supply to it. After proving power is supplied to the furnace. I would start thinking the board is bad.

  There could be other odd things causing your problem. But we need more info to work with.