How the Propane system works

[DoItAll]

Originally Posted by Old-Biscuit

I'm am still not understanding the TWO solenoids.......
Are they on the same line downstream of LP Reg ?
OR do you have two different lines downstream of the LP Reg with solenoid on each line?


YES ---the solenoid is a 'parastic' draw on the battery system.
LP Detectors are wired directly from battery so that the Detectors are in service 24/7 cause LEAKS can happen anytime
Solenoids require DC to OPEN....some then drop voltage to 2 volts to keep open ---some require more voltage but ALL require constant voltage to open/stay open


NO DC to solenoid........it is CLOSED
TWO Solenoids ....BOTH need DC to be open
No DC/not open.....NO Propane flow.




Pictures of the TWO detectors and pictures of the TWO solenoids would be helpful
But it simply comes down to NEED DC to the solenoid(s)

Here are some photos.
Note that I found the Emergency Shut-off switch for the propane system. Sadly, it was in the "Run" (out) position.

[DoItAll]

Oddly, the newest of the sensors is the one 'cut out' of the system.
Even more of a puzzle is the fact that, although all the wires on the sensor were left with half of the crimp connector, the other half is nowhere to be found. All the wiring in that compartment looks 'original', sound, not messed with.
Leads me to believe that a professional did the cut-out and repaired what was left WHICH leads me to believe that it was left FUNCTIONAL

[Old-Biscuit]

OK photos help!!

This one......"Propane FILL Switch" Out for Operation/In for Filling
That is the on/off switch for the solenoid between Reg & Service Valve (High Pressure side)
Used to Isolate Propane Tank when Filling ----due to lack of easy access to Service Valve.
DC+ to Switch .....OUT position DC+ goes to solenoid to open/hold open

Need to test for DC+ to switch and that Switch WORKS.....no DC/bad switch then solenoid stays CLOSED





This picture -----Downstream solenoid
It is on Low Pressure side of Regulator.....and 'arrow' shows it is correct
That solenoid is operated by the LP Detector
DC+ to one of those Detectors...which sends DC+ to solenoid to Open/Hold Open. Detector alarms/DC gets drops to solenoid





ONE of these Detectors powered that downstream solenoid........which ever one has THREE wires
Suspect it is/was the 'yellowed' one (CCI)
Safety-Alerm combo CO/LP Detector is most likely 'Alarm' only...TWO wires/DC+to power the Detector and a Ground wire


CCI......




Safety Alert










I need to clear up a MISTAKE I posted about the WIRING form Detector to Solenoid


THREE WIRE Detector
2 RED and 1 YELLOW (or Black or White etc)


1 Red from Battery for DC+ (power for Detector)
1 Red From Coverter for DC+ (power for Detector)
1 Yellow----DC+ to solenoid (from Detector)

**Ground is thru solenoid










So got to have DC+ at BOTH solenoids

(One from that Remote FILL switch & one from a Detector)


Time to take Voltmeter and Verify:
*Got DC+ to FILL Switch
*Got DC+ thru FILL Switch
*Got DC+ to Upstream side solenoid (Before Reg).......solenoid energizes


*Got DC+ to Detector
*Got DC+ on wire to Downstream side Solenoid (After Reg_....solenoid energizes


Tank Service Valve is OPEN

[DoItAll]

"This one......"Propane FILL Switch" Out for Operation/In for Filling
That is the on/off switch for the solenoid between Reg & Service Valve (High Pressure side)
Used to Isolate Propane Tank when Filling ----due to lack of easy access to Service Valve.
DC+ to Switch .....OUT position DC+ goes to solenoid to open/hold open"
Now that makes sense to me. I'll check it first.


"ONE of these Detectors powered that downstream solenoid........which ever one has THREE wires
Suspect it is/was the 'yellowed' one (CCI)
Safety-Alerm combo CO/LP Detector is most likely 'Alarm' only...TWO wires/DC+to power the Detector and a Ground wire"
The previous owner kept good records. The newer detector came as a kit with a solenoid valve included. That sensor has four wires. Red, Green and two blacks. Instructions say to connect one black (relay) wire to red and the other to the solenoid. That IS the way it was hooked up (black and red together in the remaining half of the crimp connector).
Seems to make sense that the functioning detector would be wired to the engine battery if it can only be wired to one or the other.
You mentioned in a much earlier post something thing to the effect of '2002 ---- vintage RV. Solenoids close when energized'.
I'm going to presume that, even if that WAS the case, it's been changed with the addition of the newer valve.
Guess the right thing to do will be to start at the switch for the high pressure valve and follow the power back to the house. I have a signal generator for tracing individual wires if necessary.
Stay tuned and many thanks for all of your input.
Alex

[Old-Biscuit]

'2002 ---- vintage RV. Solenoids close when energized'.

That should have been 'DE-energized'



See pg 3
Model 70-742-R Kit -With Normally Closed relay
https://www.mtiindustries.com/PDFs/rv/70_Series.pdf



Red wire...DC+
Green.......DC-
Either one of the Black...connected to the Red
Other Black........to solenoid


(Wiring diagram uses Red/DC+, Black/DC-, 2 White for connection to Red and solenoid)

[DoItAll]

Well, that was a head scratcher!
With the guidance and advice of "Old-Bisket", I began tracing power from the emergency shut-off switch. It lead directly to the high pressure solenoid valve (first one in the line and right before the regulator).
No problem there. 13+ volts.
So I checked the next (low pressure) valve. No power!
I checked the (original) detector and, although it seemed to be functioning (after pressing the test button)and there was power on one side of the relay, nothing was coming out.
I connected the input to the output and tested the valve.
Nothing!
I decided to trace the wires from that solenoid (that's no fun) and found that they ran into the area where the new sensor had been wired. Even had half of a crimp connector on it. BINGO!!
Sure enough, when connected to 12 volts, I could hear the solenoid clicking. However STILL no gas!
I wondered if the check valve had been 'activated ' so I closed it, waited a while and opened it ----- really slowly.
NOTHING!
After double checking that there WAS propane in the tank AND feeling around the high pressure solenoid with a steel screwdriver, decided to check the continuity of that coil.
It was OPEN!
I removed the coil and placed a magnet on the core.
Went into the house and turned on a burner.
VOILA! We have FIRE!!!
Tomorrow I will RE-wire the new detector and, providing it relay is functional, I think we're ready for our first trip.
Many thanks to all of you for your help and advice.
I'll confirm that this issue is solved as soon as I replace the solenoid and finish the wiring.
Alex

[Ray,IN]

Originally Posted by DoItAll

I'm referring to the valve that is opened while filling the tank.
It's right beside the fill port and usually says something like 'fill until liquid is visible'.
You just open it by hand, like a water valve only smaller.

That valve will emit vapors is there is ANY LP in the tank, it spits liquid when the tank is full to the valve (it's called the 80% valve or spitter valve).

[Old-Biscuit]

ALex.........
THANKS for the update and resolution (get that high side solenoid replaced) then good to go!!

[DoItAll]

Originally Posted by DoItAll

I'll confirm that this issue is solved as soon as I replace the solenoid and finish the wiring.
Alex

We just got back from a 3 day test trip and the propane system is working perfectly!!
The stove, refrigerator and furnace all worked as designed as does the emergency shut-off system. I haven't tested the water heater yet.
I would like to thank all of you for your advice and suggestions. This group is one of the most helpful I have ever encountered.
Alex

[Swampy52]

Originally Posted by DoItAll

Recently purchased a 2002 Coach House 232.
Our first RV and we're really pleased with it for the most part but the propane system is a bit of a mystery.
User interface shows the tank is 3/4 full but I don't trust that.
However, I have opened the 'full' valve and there is gas in there.
There is a solenoid valve downstream of the regulator and, as far as I can tell, it is not being energized.
Have tried both the burners and the 3 way refrigerator without luck.
Can anyone tell me what energizes that valve?
Switches on the burners?
Is there any wiring diagrams available for this RV?
Please share your thoughts, I'm baffled.

DoItAll, if you are sure you have propane in the tanks, you should be able to just turn on the stove valves and light the burners and oven pilot light with a match or lighter. Some stove tops and ovens may have igniters, but those are not connected to any power source and operate like the igniter on a BBQ grill ... just push the button. If the gas is not getting to the appliances, you may have a bad regulator or a kink in the hose to the appliance. If your appliance is in a slide-out, there is a good chance the hose may be kinked. (Common problem.)
The water heater, fridge and furnace all require 12V DC in order to operate on propane. If your regulator is OK as well as the supply lines, check the 12V fuses for those appliances. If it is more than anything I've mentioned, your best bet is to have a technician diagnose the issues for you and then resolve the problems.
Best of Luck & Good Camping ..... Swampy

[Gary H]

That valve is usually controlled by a Leak detector in the coach usually near the floor, some have an on-off switch on them and it must be on and reset to allow gas to flow. Also don't know the age of the unit but they normally are replaced every 5 yers or so, if not working then I would replace it.

[THenne1713]

If not a LPG Alarm Reset issue, see if it is wired; 2-power wires, 1 switch wire?

[fleatools]

Just a thought, remove the solenoid valve. I do not have one on my coach and it will pull current when trying to boon dock. Sounds like just another point of failure but I understand the safety factor of it too. Glad you got it fixed.

[bobfrommaine]

On older units there may be a separate 12V switch to turn on the solenoid. That switch may also be wired in series with your propane sniffer. All boats have a separate on/off switch for propane but that's because propane is heavier than air and you really don't want propane to settle in the bilge. They also have sniffers as mandatory equipment but the sniffers are simply alarms, not automatic shut-off's.
I'd recommend looking for a switch or a 12V circuit breaker labeled 'propane'.
Bob '14 Winnebago 37F Adventurer; Jeep toad.