Furnace Damage?

[monitormix]

Hi all,
So after coming back from camping, we cleaned out the trailer and buttoned everything up. While tweaking my Bogart TM-2030, I heard the furnace come on. Apparently we left it on, but the propane was off. Did we inadvertently
damage the furnace in any way by it trying to fire with no propane?

I did turn the propane back on to verify it would heat up and warm air did come out of the registers. Oddly after I turned the propane off and ensured the thermostat was off I smelled a little propane. Figured it was just residue from the quick test I did.

Fast forward 2 hours later and the CO2 monitor is going off. Opened the vents and turned on the Maxx fan. The propane was still off. Bled off the remainder propane by running the stove dry.

Any thoughts?

Thanks,
Jose

[bobbecky]

You did no damage, no different from just running out of propane. The age of your rig indicates your CO (carbon monoxide)not co2, sensor is probably due for replacement, so you need a new one, and this was just a coincidence that it said ‘replace me’ about when your propane ran out.

[monitormix]

Thanks. Although out of sheer paranoia, it now smells strongly of LPG in the coach. Guess I'll be checking the fittings to the furnace and stove tomorrow. Especially they're next to each other and the C02 detector is next to the stove. Never a dull moment...

Of course the start of the trip the deadbolt failed and I had to have it drilled out and replaced with a nice digital RVLock

[Steveo57]

The CO detector shouldn't be going off if you don't have any gas appliances running in the trailer. Could it be the propane leak detector that's going off? Are you plugged in to power? They will alarm if the battery is going dead.

[monitormix]

Yes plugged into 30A shore power. It was the detector down low next to the power center.

[jasin1]

Originally Posted by monitormix

Thanks. Although out of sheer paranoia, it now smells strongly of LPG in the coach. Guess I'll be checking the fittings to the furnace and stove tomorrow. Especially they're next to each other and the C02 detector is next to the stove. Never a dull moment...

Of course the start of the trip the deadbolt failed and I had to have it drilled out and replaced with a nice digital RVLock

Originally Posted by monitormix

Yes plugged into 30A shore power. It was the detector down low next to the power center.

Be very careful with propane leaks... if it smells strongly of propane then I would CAREFULLY verify both tanks are shut off... then open the trailer door and let it air out naturally.. I wouldn’t be flipping light switches and turning on fans or anything electrical.
All it takes is one spark from a relay or switch to cause an explosion.
If your not capable of leak testing with soap bubbles or a portable lp detector to find and correct then I wouldn’t attempt.
I’m thinking you probably left one of the stove burners slightly on when you tried to burn off the lp after you shut the tank off. One of the tank valves may not seal properly and is in effect “ passing some gas”

[rhagfo]

Originally Posted by monitormix

Yes plugged into 30A shore power. It was the detector down low next to the power center.

That is likely the propane gas alarm. Time to be checking connections, and/or stuck valve on the furnace.
Just a thought I always liked natural gas for heating cooking and BBQ at home, so gas in the trailer was a normal, I always left the gas on if on the road or in storage. My thought was I never turned off at home, why in the RV.

[travelin texans]

Originally Posted by rhagfo

That is likely the propane gas alarm. Time to be checking connections, and/or stuck valve on the furnace.
Just a thought I always liked natural gas for heating cooking and BBQ at home, so gas in the trailer was a normal, I always left the gas on if on the road or in storage. My thought was I never turned off at home, why in the RV.

Plus if you've got the typical rv fridge set to "auto" once you unplug the shore power it should automatically switch to LP if the bottles are open, otherwise you'll have no refrigerator cooling while traveling.
That detector is a combination CO/LP detector hardwired directly to the batteries. It's either due replacement (5 year typical lifespan with date in the back), sniffing LP (just FYI, aerosol sprays will set it off & if your dog lays near it & breaks wind it'll go off), there's nothing burning so no CO should be present, or your batteries are very low or dead.
I'd check all the LP fittings with soapy water, check detector date replacing if necessary, check the water level in your batteries, topping off with distilled water if needed & if necessary have them load tested at your local auto parts store.

[JRTJH]

Most LPG detectors will alarm if the 12VDC source is low. If there was no "problem with gas leaking" before this event, it's very unlikely that there is "gas leaking" now... While it's prudent to verify there is no gas leak, I wouldn't suspect that "suddenly something broke loose"...

I'd suspect that with the trailer unplugged, once you turned off the propane tanks but left the thermostat on, when the trailer cooled down, the thermostat called for heat, and ran through the ignition sequence 3 times, then locked out. Which is normal operation.

Then, after a couple of days, with the "parasitic drains in the trailer" the battery voltage dropped below the minimum and the LP Gas detector is "squaking to tell you it can't monitor properly because the voltage is too low"...

If you smell propane now, I'd investigate the source, but would not suspect a "sudden leak where there was none before, especially since the trailer has not moved"....

Additionally, the LP Gas detector has a "replace on date" stamped on it. It may be in the form of "Replace 5 years after manufacture date" or the message may be constructed some other way, but pull the 4 screws that mount the LP Gas detector, look at the data plate and it will tell you if the service life is expired. Also, it will "chirp" to tell you that it's time to replace it. The "chirp sequence" for various messages is on a decal stuck to the LP Gas detector.

I'd turn off the propane tanks, open up the trailer, air i tout, then when you don't smell propane inside, plug in the shore power, charge the battery, close up the trailer, turn on the propane, purge the lines by lighting a stove burner and then turn on the water heater (make sure there's water in it). Once you know the water heater is working, turn the thermostat to heat and test the furnace. It should work normally and you should not smell propane.

Once that is accomplished, verify that the LP Gas detector green light is on. That should give you reassurance that everything is back to normal....

I'd guess it was a low battery causing the LP Gas alarm.

[monitormix]

Well checked all connections, seems tight. Awaiting a gas sniffer to arrive from Amazon along with a slack tube to have to test any further issues. No propane smell this morning. Furnace still running properly.

If anything it seems like the hi temp burner on the stove seems to seem a little after running it.
And it was the propane/gas detector that set off. It's almost at the end of its life expectancy.

Strange. Have main propane tank on everything off in the coach. will check again in a bit to see if I smell anything.

[monitormix]

Also, when not plugged into shore power, I have a 575w solar array via my Trimetric TM/SC-2030 combo that keeps the batteries topped off when in storage.

Batteries have been equalized and are fully topped off.

Not a low battery condition.

Thank you everyone for all your assistance and knowledge.

[jimborokz]

One time our detector kept going off and we thought we could smell gas. Turned out a plate on one of our batteries shorted out and it was boiling and gassing off like crazy. Disconnected that battery and removed it and no more issue. Apparently that gas is similar to propane and will set off detector.