Propane overfill

[slowlanelife]

Our RV service people overfilled the propane tank on our Class C. We didn't know this until we took it out on a short trip. Our stove works and the refrigerator works on LP also. The water heater and furnace will not even try to fire. Any thoughts on purging out some gas? The needle on the gauge is way past full, as far as it will go. I'm running the stove on and off when I get a chance but it gets hot on the microwave above even with the exhaust fan running so I can't just walk away and let it run for hours. The dealer is some distance away. I had them fill it while it was there being serviced. You'd expect they could fill up a tank without screwing it up wouldn't you? Any help would be appreciated.

[Firedog53]

I assume you have an installed tank and not portable/removable ones. Regardless, the tank should be overfill proof; these have a relief valve that should operate at 80% full of capacity by venting vapor to atmosphere. Your furnace and water heater are probably furthest from the tank and will require some time to purge air from the lines and system before igniting. Turn on one at a time and give it a chance; it'll probably light and die a few times before staying operational as it purges the air.
I can't imagine it being overfilled, even by an idiot dealer; most pumping systems have shut-off regulators that automatically operate and RV tanks systems have a volume operated pressure/vapor relief set for 80% capacity.
If no joy with the above, try closing the main tank valve then s-l-o-w-l-y reopening to prevent system shock that can close in-line rupture valves. If all else fails take it to a LPG dealer that know systems; stay away from the RV dealer who may not know systems.
Your WH and furnace may not be receiving an electrical command--check the breakers...
Good luck...

[twinboat]

If they over filled it, it needs repair.

It has a built in overfill device in the fill port, so it should never be over filled.

The gauge may be broken, what makes you think its over filled besides the gauge ?

There is a bleed screw on the side of the tank. That's at the full mark of the tank.

Open it and watch and listen as it hiss' gas. If it spits vapor and a small cloud of propane, then its over filled. If not, the tank is not over filled.

[twinboat]

Originally Posted by Firedog53

I assume you have an installed tank and not portable/removable ones. Regardless, the tank should be overfill proof; these have a relief valve that should operate at 80% full of capacity by venting vapor to atmosphere. Your furnace and water heater are probably furthest from the tank and will require some time to purge air from the lines and system before igniting. Turn on one at a time and give it a chance; it'll probably light and die a few times before staying operational as it purges the air.
I can't imagine it being overfilled, even by an idiot dealer; most pumping systems have shut-off regulators that automatically operate and RV tanks systems have a volume operated pressure/vapor relief set for 80% capacity.
If no joy with the above, try closing the main tank valve then s-l-o-w-l-y reopening to prevent system shock that can close in-line rupture valves. If all else fails take it to a LPG dealer that know systems; stay away from the RV dealer who may not know systems.
Your WH and furnace may not be receiving an electrical command--check the breakers...
Good luck...

Your correct in it not being overfilled but your explanation is inaccurate.

The tank has the device to stop the gas from flowing in, not the pump in the filling station

If over 80%, the relief valve does not vent to atmosphere, that would be dangerous. It would just fill to 100% and stop.
The relief valve would then vent when the liquid warmed and expanded.

[Ljwt330]

The previous posts are correct about the remote possibility of an overfill. More important, your description is not consistent with an overfill problem.

First, your stove and refrigerator both work, that means gas is flowing from the tank.

Second, you have a system regulator, just after the tank valve, that reduces pressure throughout the system to 0.39 psi. That will not change regardless of pressure in the tank.

Third, both the water heater and furnace have an electronic ignition. Can’t say if your comment about neither even trying to fire was just hyperbole, but if neither makes a “ticking” sound when first turned ON, then it is an electrical issue, not gas. As Firedog53 posted, they may not be getting 12v.

You need to trouble shoot the water heater and furnace and clearly report exactly what happens, or doesn’t happen, including any lights or sounds, when you turn them ON.

[Old-Biscuit]

Originally Posted by Ljwt330

The previous posts are correct about the remote possibility of an overfill. More important, your description is not consistent with an overfill problem.

First, your stove and refrigerator both work, that means gas is flowing from the tank.

Second, you have a system regulator, just after the tank valve, that reduces pressure throughout the system to 0.39 psi. That will not change regardless of pressure in the tank.

Third, both the water heater and furnace have an electronic ignition. Can’t say if your comment about neither even trying to fire was just hyperbole, but if neither makes a “ticking” sound when first turned ON, then it is an electrical issue, not gas. As Firedog53 posted, they may not be getting 12v.

You need to trouble shoot the water heater and furnace and clearly report exactly what happens, or doesn’t happen, including any lights or sounds, when you turn them ON.

Along with Brand/Model of furnace and water heater


Course could just be propane has not been fully established at either ---furnace and/or water heater and my just need several attempts at lighting

Provided that the spark electrodes are firing CLICK, CLICK, CLICK

[Firedog53]

Originally Posted by twinboat

Your correct in it not being overfilled but your explanation is inaccurate.

The tank has the device to stop the gas from flowing in, not the pump in the filling station

If over 80%, the relief valve does not vent to atmosphere, that would be dangerous. It would just fill to 100% and stop.
The relief valve would then vent when the liquid warmed and expanded.

I've seen pumping stations with a pump shutoff that occurs when the OPD operates. Many don't have this feature.

Where else would the relief valve vent to other than atmosphere? Isn't its purpose to get rid of the excess pressure to/in the tank? Lesser of two evils, so to speak...
That's why LPG tank compartments are not fully enclosed; so that vapors can escape and be diluted without a bad event; liquid bad, vapor good. I think we're on the same track, just different ways of expression...!

[Old-Biscuit]

Originally Posted by Firedog53

I've seen pumping stations with a pump shutoff that occurs when the OPD operates. Many don't have this feature.

Where else would the relief valve vent to other than atmosphere? Isn't its purpose to get rid of the excess pressure to/in the tank? Lesser of two evils, so to speak...
That's why LPG tank compartments are not fully enclosed; so that vapors can escape and be diluted without a bad event; liquid bad, vapor good. I think we're on the same track, just different ways of expression...!

I think 'twinboat' was clarifying LP tank features/components
OPD...Overfill Protection Device----part of Fill Valve---shuts off propane liquid flow at 80% tank capacity

Overfilling would not cause relief valve to open
Overfilling and then pressure increase due HEAT (ambient air temps/sun) and lack of head space will cause it to open

Excess Flow Device......trips/limits propane vapor flow thru system due to imbalance in pressures
Opening Service valve too quickly trip it ----SLOWLY opening service vapor valve allows system pressure on both sides of LP Reg to equalize

Same train of thought...just correction of nomenclature



Which OP would respond to questions

[Bigd9]

Originally Posted by slowlanelife

Our RV service people overfilled the propane tank on our Class C. We didn't know this until we took it out on a short trip. Our stove works and the refrigerator works on LP also. The water heater and furnace will not even try to fire. Any thoughts on purging out some gas? The needle on the gauge is way past full, as far as it will go. I'm running the stove on and off when I get a chance but it gets hot on the microwave above even with the exhaust fan running so I can't just walk away and let it run for hours. The dealer is some distance away. I had them fill it while it was there being serviced. You'd expect they could fill up a tank without screwing it up wouldn't you? Any help would be appreciated.

You have gotten some great responses here Slowlanelife. What is your status right now? Still having problems? What RV do you have?

[twinboat]

Originally Posted by Firedog53

I've seen pumping stations with a pump shutoff that occurs when the OPD operates. Many don't have this feature.

Where else would the relief valve vent to other than atmosphere? Isn't its purpose to get rid of the excess pressure to/in the tank? Lesser of two evils, so to speak...
That's why LPG tank compartments are not fully enclosed; so that vapors can escape and be diluted without a bad event; liquid bad, vapor good. I think we're on the same track, just different ways of expression...!

The relief valve is set around 375 PSI.

The fill stations pump relief valve will be set much lower then that, no more then 200 PSI.

Both the bulk tank and RV tank are at near the same PSI, unless the RV tank was totally empty.
As the liquid is pumped in, any vaporized gas will turn back to liquid at between 100 and 200 PSI, so no PSI rise.

When the overfill valve closes, the liquid stops at the fill valve and the pump just recirculates the liquid back to the bulk tank.

[Firedog53]

Yep, we're all just syntaxing (is that a word?).

Also wish OP would check back in. Maybe he ignited...?

[slowlanelife]

Thanks for all your help. Yesterday I had time to to try some of the suggestions. I opened the bleeder valve and got the hissing but no vapor so the tank is not overfilled as I thought. With the water heater I am getting the clicking as it tries to light but it doesn't light. I haven't actually used it on gas in a very long time, only on electric, so that issue may be from lack of use. The reason we were at the dealer in the first place was to have the AC/Heatpump replaced. The furnace, which we had used fairly recently, doesn't click/ try to light. When I switch to furnace on the themostat I can hear the click by the furnace like I normally would. Then after 15 seconds or so it would click and try to light, but it does not do that. Fuse and breakers are ok. Maybe the AC replacement goofed something up there. I will take it back to have them look at the furnace and water heater. It may take awhile to get back in as they are very busy but luckily I can get along without these two components. I will report back here when things are resolved. When I had emailed the service people with my thoughts that it was overfilled they emailed back that I should try to get the pressure down by running the stove. If they'd told me it was nearly impossible to overfill and to check that bleeder valve it would have spared me some anxiety. I'm grateful we have the forum to turn to at times like this and I appreciate all the help and suggestions.

[slowlanelife]

Sorry, forgot to add that this is a Class C with a permanent tank.

[Persistent]

Old Biscuit is the resident authority on propane appliances. I just pretend I know what is going on.

Water heater:

It sounds like different problems with water heater and furnace. Water heater clicking indicates it has 12 volt supply and is trying to light. If the burner does not light it will cycle through the start sequence 3 times then fault. Turn it off. Turn it on it will repeat.

Gas valve opens often causing a click.
Spark igniter sparks causing loud clicks.
Burner lights.
Heat from flame heats sensor.
Gas valve stays open if heat detected. Gas valve closes if no heat detected.

Burner tubes in the heater may be plugged. Little creatures like to make homes in them. Even a small spider can block the gas mixing tube and prevent ignition. Clean it out and try again.

Observe the starting sequence from close up. Have someone turn it off and then back on while you watch the burner.
Does the gas valve click open?
Does spark igniter spark?
Does flame appear?

Furnace:

Furnace fan runs for a few seconds.
Gas valve opens.
Igniter clicks.
Gas flame ignites.
Heat sensor reports heat. Furnace continues to run.
Like the water heater, furnace will try to start 3 time and then fault.
Turn it off and on to reset.

Closely observe the starting sequence. Where does it fail?

It sounds like you reported that the furnace fan does not run. If so, the furnace may not be getting 12 volts or thermostat is not working.