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Patti Brown · 12-29-2017, 08:38 PM

Have plenty of LP. Furnace will not turn on and stay on. Shut off during the night last night (brrrr). Finally got it to stay on most of today, when it warmed up enough for the HP to turn on. Tonight furnace again will not fire up. What should we check?

BFlinn181 · 12-29-2017, 08:45 PM

What is the make and model # of your furnace? A search on Google with that info should yield a service manual and troubleshooting guide.

The sequence should be, Furnace fan on, when it's up to speed the gas valve should open and the ignitor should light the gas. If the flame isn't detected (by a very weak current flow through the carbon atoms in the flame) it shuts down the gas. After 3 failed cycles, the furnace goes into lockdown and has to be turned off and on again to reset.

Bushy · 12-29-2017, 08:49 PM

I admit that I'm really reaching here but you sound desperate...
Sometimes propane fired appliances act like what you're describing when the tank is filled too full and not properly bled. Does the stovetop work properly? And the fridge? I'd suggest turning on the stove for a bit. Then try the furnace again.

Ricci · 12-29-2017, 08:51 PM

Hi - You don't say where you are or the overnight temperatures but if it is cold and the furnace runs well during the day(warmer temps) I think you have moisture in your propane tank. It causes the pressure regulator to freeze and cuts the propane supply to the furnace (or cuts the pressure low enough to shut it down). You need to find a good LP gas place and have them inject some methanol. In the meantime if you can wrap the regulator in something that will keep it warm that will get you through a night or two. Northern LP stations will do a winter mix but in the south it is rare. When it warms up the issue may go away but you still need to get the moisture out of there.

Tom

BFlinn181 · 12-29-2017, 09:15 PM

Quote:

Originally Posted by Ricci

Hi - You don't say where you are or the overnight temperatures but if it is cold and the furnace runs well during the day(warmer temps) I think you have moisture in your propane tank. It causes the pressure regulator to freeze and cuts the propane supply to the furnace (or cuts the pressure low enough to shut it down). You need to find a good LP gas place and have them inject some methanol. In the meantime if you can wrap the regulator in something that will keep it warm that will get you through a night or two. Northern LP stations will do a winter mix but in the south it is rare. When it warms up the issue may go away but you still need to get the moisture out of there.

Tom

Just wrapping a metal valve with "something to keep it warm" will do nothing because you have to add heat for the insulation to trap the warmth. You could use a trouble light to heat the regulator above freezing. Then drape it with "something that will keep it warm." If you stove, refrigerator, and LP water heater work as they should, you don't have a freezing regulator.

Patti Brown · 12-29-2017, 09:34 PM

Overnight temps in the mid thirties. Just cold enough to limit the HP. Tank was reading 1/2 full. After just one day it is now reading 1/4. We have shut the valve pending figuring this out...I am a Deep South gal and get wimpy in moderately cold weather, but will tough it out for tonight. And tomorrow is another day...

Thanks for the helpful ideas. Keep them coming! I am always so grateful for the help provided via this forum!

guardrail53 · 12-29-2017, 09:47 PM

Sounds like you have a sticking gauge, tap it with a wooden/rubber end of a screwdriver, and see what it does! and go get it filled! JMHO! Rail!

blang · 12-30-2017, 05:56 AM

If the stove works, here are a couple of things to check on the furnace. I don't know what furnace you have but this info applies to my Suburban furnace.

If the blower fan gets dirty enough, it doesn't move enough air to trip the sail switch. Additionally, the sail switch can be dirty impeding its' ability to move. Either condition will allow the blower to turn on but the gas valve will not open and fire.

The fix is to go outside, unscrew the furnace access door, find and unscrew the rounded plastic cover on the squirrel cage blower. Clean the blower wheel with a vacuum paying particular attention to the inside curve of the fins. Also, on the underside of the rounded cover you removed is the sail switch. CAREFULLY vacuum any dirt. Be careful, that little fin sticking out is delicate. Put back together and, hopefully, fire up your furnace.

If that sail switch is not moving freely after vacuuming, a little shot of wd-40 might make the difference. If not, that switch is on Amazon for, if I remember right, about $16.

PS: The above is just from my experience on my furnace and I admit to knowing almost NOTHING about much of anything else. LOL It's entirely possible that your problem has nothing to do with the above but, when you're cold and the above simple fix may allow your furnace to kick on and begin throwing heat, you'll find that result as sweet as I did.

tmw188 · 12-30-2017, 06:14 AM

I assume you have shore power being you mentioned the HP.
Maybe you are running the gen in either case a couple of portable electric heaters should get you by until you find the problem. I like some of the ideas others have posted let us know how it turns out.

Ricci · 12-30-2017, 06:59 AM

Hi Bob - "something to keep it warm" in my mind implied that there was a safe source of heat such as an electric heating pad. Sorry if I wasn't clear.
Tom

"007" · 12-30-2017, 07:30 AM

There was a time that LP gas was different in the south as to the north reagin and you could run into problems with the southern region LP up in the colder temps you encounter up north.
Check your outside vents and make sure they are clear from blockage such as mud daubers inside tubes, poor venting will over heat and limit sensor will shut down furnace.

GaryKD · 12-30-2017, 02:31 PM

Hi Patti Brown,
Gut feel says it is the regulator. Any RV store carries them for about $25. It is an easy unfasten put the new on and tighten the connections. The regulator is next to the LP tank. Make sure you install it in the same attitude as the old regulator. Usually flat with the ground. The furnace is a very high propane usage appliance. If the stove and water heater work then it is the regulator.

Quincy · 12-30-2017, 04:23 PM

All the above suggestions have some merritt but if you go at this like a repair tech you must check the obvious and easiest fixes first then move to more and more complicated and difficult fixes as you proceed. First check the filter and make sure it is clean or replaced. If the air dosent move the unit will overheat and turn off on the high limit switch. Next is the blower motor even starting or staying on if it does starts. Either way there might be a run capacitor on the blower motor and this should be determined ok before suspecting the motor itself. If the motor comes on and stays on is there any obstruction blocking the ductwork? Now I can not speak to any electronics that are present in the newer rigs heating systems but at this point you are past the basics and looking for more complicated and or less obvious solutions. If you are still having an issue post again and we can start banging our heads together.

Good luck and keep us posted.

Russtj60 · 12-31-2017, 06:17 AM

Quote:

Originally Posted by Patti Brown

Overnight temps in the mid thirties. Just cold enough to limit the HP. Tank was reading 1/2 full. After just one day it is now reading 1/4. We have shut the valve pending figuring this out...I am a Deep South gal and get wimpy in moderately cold weather, but will tough it out for tonight. And tomorrow is another day...

Thanks for the helpful ideas. Keep them coming! I am always so grateful for the help provided via this forum!

My first step in troubleshooting this is to fill the propane tank. Both previous coaches have shown degraded performance in colder temps when the tank level was at or below 1/4 full in cold weather. After that heating pad on regulator and then more intrusive checks. I like the KISS approach.