no heat, fan runs.

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fredf

Member

• Dec 24, 2013

• #1

When I turn on the thermostat, the fan comes on but no heat. I left it for an hour on 70, but no heat, only air for the registers. It seemed to work yesterday. We have had a snowstorm and freezing rain. I shoveled around the AC unit on the roof. Any simple ideas before i take it to the dealer? Gas stove works

Fred

 

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Phil Smith

Retired South Carolina Chapter Leader

• Dec 24, 2013

• #2

Sounds like a possilbe issue withthe sail switch. The fan closes the sail switch to allow gas flow to the burner.

 

danemayer

Well-known member

• Dec 24, 2013

• #3

Hi Fred,

Is the fan pushing cold air, or lukewarm air? If lukewarm, you probably have a problem with insufficient gas flow. Close the propane tank valves, wait 20 seconds and open VERY slowly to avoid triggering the overflow protection device. Also, try swapping tanks.

Are any of your heat registers restricted/covered/block or is the air return blocked? If so, you may be triggering an overtemp condition in the furnace.

 

jimtoo

Moderator

• Dec 24, 2013

• #4

You don't have posted what kind of Heartland you have, but my question is why did you shovel around the A/C? The fan you have running and getting air from,,, is it for the heater and your getting air from the floor vents? Or are you getting air from the A/C vents?

If you have an A/C with heat pump, I don't think you will be getting any warm air as they only work down to about 35* or so. If you do not have heat pump and getting air from A/C vents and not floor, then you have the thermostat set wrong, the FAN should be on AUTO on the thermostat. The switch on the thermostat should be set to HEAT.

Let us know what you have and what happens.

 

ramdually4100king

Well-known member

• Dec 24, 2013

• #5

Our cyclone did this. We had a repairman come out and he replaced the control board on the heater. Since then all is working great.

 

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fredf

Member

• Dec 24, 2013

• #6

Thanks for the answers. I have a Big Country. Where do I find the sail switch? Where is the air return? I don't think I have a heat pump. I don't know why the AC fan comes on when I turn on the furnace switch. But it does. I also can feel air blowing out of the floor vents.
I don't haave an auto switch on my domestic thermostat. just fan,cool,furnace. I set it on furnace, of course, and set temp to 70 degrees.

 

jnbhobe

Well-known member

• Dec 24, 2013

• #7

Turn the fan switch to auto.

 

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fredf

Member

• Dec 24, 2013

• #8

Thanks, figured out how to put the fan on auto. This turned off the AC fan. The heat fan came on for 20 seconds as the manual said, but then nothing.

Fred

 

danemayer

Well-known member

• Dec 24, 2013

• #9

If the A/C Fan is running when you call for heat, it's because the thermostat's fan setting is on HIGH or LOW instead of AUTO. Cycle the thermostat to FAN mode and press the + or - buttons to change the setting to AUTO, then cycle the thermostat back to HEAT mode.

The sail switch is in the furnace assembly. The air return location varies by floorplan. It's typically a large grate on one of the walls near the furnace.

You might want to take a look at our owner-written Heating and Cooling Guide to get a more thorough understanding than the dealer gave you in your walk through.

 

danemayer

Well-known member

• Dec 24, 2013

• #10

fredf said:

Thanks, figured out how to put the fan on auto. This turned off the AC fan. The heat fan came on for 20 seconds as the manual said, but then nothing.

Fred

Click to expand...

After the furnace blower starts, the furnace uses the sail switch to ensure there's enough air moving and if the switch works there will be 3 attempts to ignite the propane. After that there's a lockout for safety reasons and you have to cycle the thermostat to OFF and back to HEAT before it will retry.

Have someone else do the thermostat reset while you're standing outside by the furnace to see if it sounds like it's trying to ignite. If yes, it's probably a propane flow or other ignition problem. If no, it's probably the sail switch, but could also be a problem with the circuit board.

Low 12V power can also cause this type of problem. If the power converter stops working and the battery is running down, you can get symptoms like this that worsen as the battery gets lower and lower.

 

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fredf

Member

• Dec 24, 2013

• #11

Low 12V power can also cause this type of problem. If the power converter stops working and the battery is running down, you can get symptoms like this that worsen as the battery gets lower and lower.
Dan, I have my Big Country hooked to house 110V power. Could this still be the problem. Would hooking the 5th wheel to my PU maybe solve the problem?
Fred

 

danemayer

Well-known member

• Dec 24, 2013

• #12

fredf said:

Low 12V power can also cause this type of problem. If the power converter stops working and the battery is running down, you can get symptoms like this that worsen as the battery gets lower and lower.
Dan, I have my Big Country hooked to house 110V power. Could this still be the problem. Would hooking the 5th wheel to my PU maybe solve the problem?
Fred

Click to expand...

Fred,

The power converter changes the 110V shore power to 12V to feed the 12V fuse box and charge the battery. If the converter is unplugged, or failed, or blew a fuse, or it's circuit breaker tripped, you're totally dependent on the battery to run your lights, thermostat, furnace, refrigerator circuit board, etc. even though plugged into shore power.

Before you go too far down this path, check the control panel inside the coach. In addition to showing tank water levels, it also shows lights that indicate your 12V status. If all is well, you'll see all the lights lit up.

If the control panel lights don't all light up, hooking up to the truck may help for a while. But running the furnace that way could also run down the batteries on the truck.

If the converter has failed, you can get a battery charger from Walmart and hook it up to the battery as a workaround. It may supply enough power to keep the furnace running.

 

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fredf

Member

• Dec 24, 2013

• #13

Dan,
Control lights for battery are all lit and power surge protector showing green light. Lights work in the RV.

Fred

 

danemayer

Well-known member

• Dec 24, 2013

• #14

fredf said:

Dan,
Control lights for battery are all lit and power surge protector showing green light. Lights work in the RV.

Fred

Click to expand...

Time to check LP supply and to see if the furnace it trying to ignite the gas. Close the propane tank valves, wait 20 seconds, open the valves VERY slowly so the overflow protection device doesn't trigger. If it still doesn't work try swapping tanks. If still a problem, have someone else operate the thermostat and listen to determine if the furnace is trying to ignite.

 

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fredf

Member

• Dec 24, 2013

• #15

Had one of the tanks filled this afternoon- only took 2 gals. Tried turning on the valves very slowly. Also, the gas stove works (all three burners)so I must be getting gas. I can't talk my wife into going out to turn the furnace on in her PJs so will have to wait till tomorrow for that. Thanks
Fred

 

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fredf

Member

• Dec 25, 2013

• #16

I can not hear the furnace trying to ignite.
Fred

 

danemayer

Well-known member

• Dec 25, 2013

• #17

fredf said:

I can not hear the furnace trying to ignite.
Fred

Click to expand...

Probably the sail switch or circuit board. Time to call for a service tech.