Truma Varioheat middle of the night ignition failure lockout

[DanielBoondock]

Couple times on our March trip back from the factory the cabin heater got stuck. No heat, loud fan blowing. Consulting with Gemini I found the following, that its probably a lockout state caused by an ignition failure. The heater is running the fan full blast to clear out the ignition chamber of unburned propane. Can be caused by a low 12V line (not the case here with the max battery pack), or a propane line drop. Low nighttime temps cause the propane to contract and lower the pressure, explaining why it only happens then. Another possibility is moisture in the tank. Being new to the trailer and it being middle of the night I didn’t catch an error code, but most likely due to this. 

Possible fixes to prevent are to …

• Go to a place that can put a little methanol in the tank prior to filling to act as an antifreeze (a bother)
• Wrap the tanks (30lb on mine) in a heating blanket (expensive at $500+ each)

The propane lines are set to 11” pressure by RV regs, so increasing that isn’t an option. 

Being out West we frequently travel between temperature extremes so I’d like to be generally prepared to prevent this from happening again. I’m wondering if there’s a low cost way tank heater blanket solution? Or other ideas, we have 30 lb tanks. 

[jd1923]

3 hours ago, DanielBoondock said:

Couple times on our March trip back from the factory the cabin heater got stuck. No heat, loud fan blowing.

"Couple times" did it ever run correctly? "Low nighttime temps cause the propane to contract" Have you tried it when it's warmer out?

Why not take time now to fix the actual issue? It's August now vs. March so certainly no need to heat tanks this time of year (if ever). And you can work on this middle of the afternoon, not waking up middle of the night. Get error codes if present.

Don't assume12V at the ignitor just because of a "max battery pack." Are you hearing ignition? Test for 12V+ and actually see or at least hear the ignitor clicking for actual verification.

Then are you getting gas? The heater fan will blow to "clear out the ignition chamber" as a process step whether LP is present or not.

Is your LP regulator supplying LP at the correct pressure? Gas in the lines? We usually light the LP stovetop to clear the lines of air but you may have an induction cooktop. Is the hot water heater working correctly? If you have the rear LP port run something back there to verify good gas flow.

We had issues our last trip out with LP keeping our older 3-way fridge running overnight. It ran fine on DC and I was worried about the new LP regulator I had installed. While parked at home this August, I ran all LP appliances to be sure (stovetop first, then the furnace, HWH and fridge). Cleaned the sail switch in the Atwood furnace which barely needed any cleaning. They all tested/worked well when at home, so my conclusion was that the old fridge will have issues running on LP when at 7600 FT elevation like our last campsite. Now is the time to get yours fixed when you're not out camping.

Some of our members from up in Montana or Minnesota can chime in, but unless you are camping regularly below 20F a heater blanket should not be necessary. LP will not vaporize at all when -44F but certainly will for occasional drops below freezing (32F).

Your Truma should still be under warranty, so you could schedule repair service. You will want to go through testing steps regardless, know that you have LP and 12V+ present and record any error codes if possible.

[DanielBoondock]

32 minutes ago, jd1923 said:

"Couple times" did it ever run correctly? "Low nighttime temps cause the propane to contract" Have you tried it when it's warmer out?

Yes of course, it’s always operated correctly but two times at night it had this issue, only in high cold temps

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Why not take time now to fix the actual issue? It's August now vs. March so certainly no need to heat tanks this time of year (if ever). And you can work on this middle of the afternoon, not waking up middle of the night. Get error codes if present.

That’s what I’m doing? 😅 Sorry but that’s the point of this, I’ve taken care of other pressing tasks on the trailer and am getting to it (along with my breakaway controller which isn’t charging)

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Don't assume12V at the ignitor just because of a "max battery pack." Are you hearing ignition? Test for 12V+ and actually see or at least hear the ignitor clicking for actual verification.

JD I’m trying to to diagnose this, of course it could be the 12V but 32 years of debugging tells me that’s not the first thing to look at. It’s a rare event that only occurred in a couple special circumstances so it’s not like I can test and measure. At any rate I live near the Pacific ocean where temps don’t get cold enough to test. 

… a bunch of good points brought up, thanks …

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Your Truma should still be under warranty, so you could schedule repair service. You will want to go through testing steps regardless, know that you have LP and 12V+ present and record any error codes if possible.

The nearest Truma center is 4 hours away and want you to leave the trailer until they can look at it in their queue. Not optimal. I know this because I’m chasing an issue with the blower fan intermittently rubbing. At any rate I’m looking into this now and gathering information so that IF I need to take it to the Truma repair I have conclusive evidence of an issue. I guarantee that if i took it now they’d say it’s fine, because it might be fine.  

At any rate with this thread I’m also looking to see if anybody else has experienced this.