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Jim_HiTek · 10-08-2015, 11:13 AM

Darn, shut off my electric propane valve yesterday before a fill up of the house tank (took 10.8 gallons). Afterwards, the flow didn't start up again like normal. The electric valve seems to be working, at least it's drawing the correct amount of amps.

But no flow to the kitchen. Checked the main manual valve at the tank...but it's On. Wondered if there's a ice block but it's now sat overnight and the same problem. No flow to the stove.

Gah! I'll be at a place where I can crawl under there and check out the electric valve later today.

Anyone think that it might still be ice at the valve? It's not gotten above 58°F here since the problem started.

dennis45 · 10-08-2015, 11:31 AM

Not sure why you think there is an ice block but I can assure you at 50+ deg ice will not form in a propane system.
Your problem is with either the shut off valve or the regulator on the tank. If you are not familiar with propane systems, I suggest calling a mobile RV service tech or take the coach in to a qualified shop. This is not a DIY project unless you know what your doing.

ahicks · 10-08-2015, 11:33 AM

First thought, the tech that filled your tank shut it off and didn't turn it back on. Second thought, the hi flow section of the regulator may have been tripped. You can try turning the gas valve off at the tank, then go in and turn the stove on for a minute to relieve any pressure in the systems. Once satisfied no pressure, turn the stove off and s-l-o-w-l-y open the gas valve at the tank. Once open pressure should be restored.

If not, my finger would be pointed at the elec. valve you're talking about, or the regulator.

rebel1155 · 10-08-2015, 12:42 PM

my lp leak detector malfunction once and shut off the gas flow to the entire rv once I replaced it everything was fine

Jim_HiTek · 10-08-2015, 09:24 PM

The propane tech told me they aren't required to turn the valve off at the tank any longer. And it was on when I checked it later. I did turn it off overnight and turned it on s-l-o-w-l-y this morning.

No change. I think I'll try disassembling the electric valve. I'm not getting any pressure past that valve that I can discern when usually I'll get at least airflow at the stove. It is 24 odd years old...and I do have a much newer one in my parts box that might fit. Made for a marine propane system but should work.

ahicks · 10-09-2015, 06:57 AM

We all have our own preferences, but if my solenoid were to go bad on ours, I'd replumb without it.

dennis45 · 10-09-2015, 09:59 AM

Quote:

Originally Posted by ahicks

We all have our own preferences, but if my solenoid were to go bad on ours, I'd replumb without it.

I agree,

Jim_HiTek · 10-09-2015, 10:56 AM

Why remove a safety device? Makes no sense to me. If you're out of the RV and the detector goes off, what happens these days without the shutoff solenoid, is that the RV fills up with deadly gas. Oh, sure, the beeper is madly beeping, but it doesn't do anything if no one is there.

A flame from the pilot light (if you have one), the refer, furnace, water heater, or your neighbor lighting a match and whoosh, your RV is on fire. And yes, it has happened. That's exactly why they required RV manufacturers to install the shut off solenoid in the first place, decades ago.

What happens with my system is if the detector senses propane, it shuts off the valve. No fire. Yea!

Since no one is concerned about the consumer these days, they let the manufacturers stop installing the solenoid just a few years ago. I think that was a very bad idea. I'm going to keep mine working as long as I own this rig.

But, back to my issue...

Hah! I'm a dummy. I'd forgotten that the solenoid needs a full 12V pulse and then the voltage drops to a holding voltage. I knew about the holding voltage but forgot about the pulse. Once I remembered that, and pulsed it, it's working and I have gas again.

Now on to repair the leak detector...I bought a new sensor module a few months ago so time to change that out while I'm fixing the detector.

Thanks for everyone's advice!

ahicks · 10-09-2015, 12:12 PM

After spending 20 years working on these things at a dealer that also sold propane, maybe I'm a little complacent regarding the necessity of the solenoid. I simply stated my thought on the issue with that experience in mind. Do as you like. No argument over it here.

If there were a concern, it would not be the fire. It would be the explosion....

wa8yxm · 10-09-2015, 04:35 PM

You shut off, and turned back on, the ELECTRIC valve.

The pump jockey turned off the MANUAL valve on the tank outlet,, What I do not know is if he turned it back on after filling.

Suggestion. Turn on as follows (If needed turn OFF tank valve for 5 minutes first)

Turn on ELECTRIC, Now Open tank valve till you just start to hear the gas flow (if you do hear it) Wait till you can hear it no more and again, Open just a little more (Till it flows) when you hit full open you should be good.

This procedure may not be needed (just opening it may work) but .. Well you can try just opening first.

Jim_HiTek · 10-09-2015, 10:35 PM

NO, wa8yxm, the pump jockey did NOT turn off the manual valve. When I asked him if he had, he said they don't have to do that anymore on RVs. I checked it anyway and yes, it was still on. I'd turned off the ELECTRIC valve and coincidently, the propane leak detector (which controls the electric solenoid) failed when I turned it back on. I was able to get gas again as mentioned above...still working on the leak detector issue.

wa8yxm · 10-10-2015, 07:48 AM

No matter what he says he should have turned it off. But if he did not, well then that's not the problem

As I understand it the Explosive Gas Detector is supposed to send an initial burst of 12 volts or there about to the solenoid for like one second then drop to a lower voltage to maintain (There is a very good reason for this) Since I do not have that kind of system I can not confirm. But if this is the case it may be the detector is not sending that initial burst.

The logic: Takes more effort to open the valve than to hold it open and the higher current flow needed to open it can overheat the solenoid and lead to burn out....

Thus they send an initial burst of high voltage/current then cut back. Takes only two componenets in the detector to do this. Less than a dollar in parts. Though might be easier with 3 parts.

Jim_HiTek · 10-11-2015, 09:40 AM

I asked him why he hadn't turned off the tank valve and he told me he'd just taken the class a few months before and that now they are taught they don't have to do that on big RV tanks.

You are correct as far as operation goes, here's what I had written on the reverse engineered schematic I'd made of the circuit back in '07. Back then I was getting lots of false trips from running the genset with windows open and added a 'bypass' circuit I designed. In addition, the Figaro gas detector was showing signs of failing but were $40 each then and I held off replacing it until recently. (Now they're $8).

"At turn on, there is a short transient of near Battery voltage to the solenoid via terminal W3 and associated wiring, then a rapid drop to a steady 3 V while the circuit stabilizes. If there is no LP gas detected, the circuit rapidly rebounds to near battery voltage at W3 for 2-3 seconds to close the gas valve, it then tapers off to a steady state voltage of 2.5V to 3.0V to hold the valve 'ON'. If there is gas detected, the beeping continues and no higher voltage is supplied to the solenoid. This circuit requires no ground. The solenoid is grounded to the chassis."

It does take quite a few more components than just 2. I count 5 transistors, 2 ICs and 70 odd discrete passive components.

I'd like to do it with just 2 components. I am having a bit of trouble with the circuit after installing the new detector. It's beeping continuously. Haven't figured out what the problem is yet. Might have to pull out my Tek scope.