LPG (propane) low voltage alarm closes the LPG solenoid valve?

[engineer bill]

On just completed trip, I had trouble getting the furnace to work - it was blowing cold air, not warm. (Unhappy wife.) Some investigation revealed that the LPG Alarm had been turned off by someone during it's recent visit to the shop. This <apparantly?> turns off the power that holds the normally closed LPG solenoid valve open, thereby causing the furnace to malfunction - i.e. blow cold air. So I turned on the LPG alarm with the toggle switch on the alarm box and bingo the heater fired up. (Happy Wife.)  So far, so good. But I'm confused because in the course of trying to troubleshoot the heater I had successfully lit the stove and then assumed that the heater was also getting LPG. What gives?

[DaveVA78Chieftain]

My guess is:
Furnace is high volume device
Stove burner is low volume device (was using residual gas present in the lines)

Dave

[engineer bill]

Dave, That is wicked good advice and it makes sense to me. I'm not planning on having any more low voltage alarms but I will check this out and get back to you. Thanks, Bill

[engineer bill]

And while we're on the subject, on my LPG Alarm, surface mounted adjacent to the battery box/step, the plastic cover has been kicked in. It seems to work ok (alarms on propane gas torch directed at it and low voltage and turns the gas on/off) but it is clearly older than it's recommended working life (5 years?) and damaged to boot. (Pun intended.) I want to replace it but having looked at a lot of new LPG alarms, none of them seem to have either the low voltage alarm function or the LPG solenoid valve shutoff function. I.E. they are two wire devices. I think I'm ok with that, based on the principal of the simpler the better, but I'm just checking with you guys to see if you have any insight that I may have missed. One more advantage of using a two wire alarm is that I could re-purpose the LPG solenoid gas shutoff valve control wires and mount a switch on my coach control panel, allowing me to turn the gas on & off as desired. I'd still want to get out and shut off the hand valve before traveling I think.

[circleD]

Please be careful when using another source of gas to test any kind of detector. This is for everyone to read. The sensors in these detectors are made for small readings and when you use a torch or lighters too close you can very easily burn up these sensors.  When haz-mat teams became normal to have and utilizing $$$$$ monitors, we would put the CO monitors next to or close to an exhaust pipe to see how quick they'd pick up  D:oH! BIG MISTAKE!! Basically when you saturate the sensor it might not work as well or at all next time. I know some of you don't put it right in front of the monitor but just keep it back and let it flow towards the monitor like it would if a leak happened.
By the way, good job on your progress Bill