Help. I need heat

[Imustbecrazy]

I'm new to the RV world. It's my wife's fault. We have a 2015 25ft Flying Cloud. Sometimes the heat goes on, sometimes it doesn't. It has a Dometic thermostat and yes, there is propane in the tanks. The coach is currently fully hooked up and parked behind our home. We seem to be able to get the heat pump to function but not the furnace. Can anybody help? I would call the dealer since I practically have them on speed dial but I would like them to think I can do something on my own. Thanks.

[SteveSueMac]

Here are a few thoughts:

1) are appliances getting propane? Is the stove working? If not, you may have a propane flow issue. Hopefully you're not smelling propane anywhere/outside the trailer?

2) you should only have one zone for your trailer - is it possible the thermostat is set up for two zones? The manual isn't terribly helpful but worth checking.

3) you say it has propane - how sure are you about that? You can pour a cup of hot water down the sides of your tanks to sort of see the line where LP is just to check.

4) try giving DW a hug and letting her know you're not really blaming her - that may remove the 3 karma demerits and fix things right up! 😂😂

Others will have better ideas for you...good luck!

On edit - are your LP tanks open? I always forget that one...

[Imustbecrazy]

Thanks for your advice. Just went out (in the rain) to check on the stove burners and lo and behold, the furnace is running. Go figure.
Good advice on the hug. Generally works well, depending on the level of indiscretion. I'll keep that one in the Trouble Shooting manual.

[sgschwend]

The furnace has a startup routine that I have found will not light if there is too much air in the propane line. Running the stove in my case helps because the two appliances are in the same place.

If your furnace does not light, then turn the thermostat off and wait a minute then try it again. eventually the air will vacate and the propane will reach the burner.

[Imustbecrazy]

Thank you. I'll try that.

[delongj]

This morning our house furnace wasn't working. I am technically inclined so I tested for 24 volts DC at the CONTROL board of the unit. No voltage. The transformer? No. It was a safety switch hidden up behind the draft! A push of a small red button and things started looking good.

My advice is to check for safety switches. Good luck AND don't forget to check out YOUTUBE videos if available. That is where I learned about "the HIDDEN safety switch"! jd

[Lumatic]

Originally Posted by sgschwend

The furnace has a startup routine that I have found will not light if there is too much air in the propane line. Running the stove in my case helps because the two appliances are in the same place.

Normally there should not be any air in the propane line, but, there will be air in the propane line if the propane tanks have been just filled. It is then necessary to bleed off the air. Using the stove burners can help to do this.

[romeb]

Whoa...what is that trick about pouring hot water on the propane tank to see where the line is? I always just guess by how heavy they are...this sound MUCH easier and reliable?

[Lumatic]

Originally Posted by romeb

Whoa...what is that trick about pouring hot water on the propane tank to see where the line is? I always just guess by how heavy they are...this sound MUCH easier and reliable?

I think it goes this way. As the propane is used it expands from a liquid state to a gas. As it expands it cools. As hot water is poured or sprayed on the tank a line will form that shows the level of the liquid propane. The tank needs to be in use. Never did it!

[Wanderer2604]

Heat is required to boil a liquid. As you let propane gas escape from the tank, the pressure drops until the boiling point of the liquid at the reduced pressure drops to the temperature of the tank and the liquid boils. Even though the tank doesn't seem hot, it is easily hot enough to boil the propane. The 'hot' tank transfers heat to the liquid propane and boils it. (At atmospheric pressure, propane boils at -40.)

If you boil the propane fast enough, the tank will give up heat faster than it can be replenish by the air, tank mounts etc. and the tank temperature drop will be noticeable. For the water trick to work on a 30 lb tank, you need to be using propane at a high rate.

If you use a disposable 1 lb propane can (lower thermal mass) with full size grill with a 'steaksaver' connector you can see this cooling dramatically. I've done this many times and frost forms on the bottom part of the propane canister if there is enough humidity to form the ice.

[guskmg]

If you are running the heat pump and the outside temp gets below 40F the furnace comes on automatically. that keep things below from freezing.
guskmg

[m.hony]

Maybe it is due to living in a geographic area with nearly 100% humidity, but I can just "see" the propane level in the tanks.
The condensation or sweat is different where there is LP in the tank vs. air at the top.
There is actually a visible line where the level is.
The weight of the tanks is actually a very good indicator.
Heavy when empty, but very, very heavy when full.
Tapping on the tanks is also an indicator. The "ping, ping, ping" will be higher pitched on a full tank and lower pitched on an empty tank.
All that aside, my tanks have gauges on them which are actually quite accurate.
Also, the monitor inside has a gauge which is fairly accurate.
We really don't use a lot of propane. It has been over a year since I filled the tanks and I still have one full tank and one half full tank.
We never use the stove.
We only use the furnace if it is too cold for the heat pumps to be effective.
We don't have any trips planned till March now, so we won't be using the furnace.
The most use of propane is probably running the refrigerator while traveling on very long trips. On trips less than 4-5 hours I just leave the refrigerator door cold. It will hold the temperature on shorter trips. It's those 8-9 hour trips that it needs to be turned on while traveling.