No heat, fan is running??

[burnt toast]

08 37x16 Just brought the trailer home from winter storage, everything seems to be working except the heater the fan is turning on and cycling for 20-30 seconds but there is no ignition of the LP. I am a new owner of it just buying it last summer used it a couple times so I'm not sure if I'm just doing something wrong? The stove is working and the fridge is working on propane. I do recall this doing the same thing last year and I can't remember what I did to fix it or if it just started working but I know I did have heat last summer.

[B and B]

Hello,
Certainly sounds like air in the lines. It might take a few tries to get it to light.

[burnt toast]

U think I have tried it like 10 times? And no igniter or solenoid clicking.

[Flybob]

Some units will go into fail safe mode after a few failed attempts. Turn it off ( not just down) and it may reset the fail safe.

[caper]

Are you on house power or running off battery? If you are on 12volt voltage might be to low to allow furnace fan motor to come up to speed.

[burnt toast]

I'm plugged into the house, batteries were pulled over the winter and are fully charged

[B and B]

Possible air intake restriction? Mouse or something like a wasp nest? Air restriction would cause issues with airflow switches/

[burnt toast]

Air flows good through the vents when the fan is running not a blocked intake

[northstar1960]

if the exhaust for the burnt gas is clogged the sail switch will not make contact and prevent ignition check your outside vents both combustion air in and exhaust out . also you could have a bad pc board , this can still allow the fan to run but not ignite the furnace . I don't know if this furnace has a lock out after so many failed attempts but like mentioned above shut the power to the unit down for a minute and then try again . if still no ignition then look into thew sail switch or pc board . you;ll have to pull the unit out

[Sac3100]

I had the same problem with mine. It turned out to be the control board. Was still under warranty so they replaced it for free for me.

[rlsmith]

or the propane valve was turned on too quickly. Turn off the propane and loosen the propane line to relieve the pressure. Slowly turn the valve back on. Turn on a burner on stove to purge air, one you have fire then turn on furnace again. Oh switch fan from on to auto, and give it a few minutes.

[mike.t]

Light stove to remove all air then Turn fan to auto.

[litgrep]

I've had many times where the tank was low but sufficient to lite stove but would not lite furnace. Switched to full tank, furnace could lite. Also, make sure you turn the gas on slow.

[northstar1960]

Originally Posted by burnt toast

Air flows good through the vents when the fan is running not a blocked intake

are you allowing the fan to run for a few mins ? it may take 30 sec's up to 90 secs or more before ingntion

[srennick]

If you have tried the power on /off and there are no vent blockages it is probably a faulty hi/lo temp limit switch. It's an easy fix on most units. The hi/low limit switch is a small unit which keeps the combustion chamber from getting too hot. If it fails it prevents the fuel from flowing to your burner. You can google your unit and get the replacement instructions. You can test yours with a simple continuity tester. Good luck. BTW they usually fail on Christmas Eve!!

[waing1]

I just had a similar issue in my case it was the high limit switch in the furnace box.

[Steve38]

Replace the sail switch. $10. You have to remove the furnace. Not too difficult.

[burnt toast]

Thanks for all the great tips guys appiciate the help I will try a few of these and report back I'm going to purge the line first right at the heater as I have been just turning the propane very quickly.

[burnt toast]

Suburban SF-35F model. I loosened off the fitting to purge the gas line at the furnace I am getting propane. I reset the master switch let it sit for five minutes did not help. Continuity check to Highlow switch was completed showing zero 00.5 at 68°F. There is no sail switch it appears to be electronic I'm thinking it's the board what do you think?

[TimVWulp]

When the furnace is tiring to light can you hear the spark igniter snapping tiring to light the pilot. If not then the you my have problem with the electronic ignition board or a spider net was built over the pilot and igniter shorting it out and not allowing the furnace to start. Is the tt plugged into 110 volt power. Battery may not have enough power to operate the furnace properly.

Hope this helps Tim