Propane leak

[mariaandskip]

Turned on the propane tank valve. Stove works, Furnace works. turn off both and go eat lunch. I come back to the propane detector is beeping. Open the door and turn on a fan to clear the air. I then make a soap solution and check the fittings, no bubbles. I close things up and check back a few times. It must be a slow leak because it takes about 1/2 an hour till the alarm goes off. I buy a sniffer from Amazon and check joints inside the RV and get nothing[B]. I went outside to check and got a barely noticeable beep from the furnace when I opened up the access panel. I taped a piece plastic over the opening. In about 10 minutes I poked a hole in the plastic and stuck the sniffer wand in the hole. Got a high reading. Sprayed more solution and still no bubbles.

I called a mobile RV tech figuring they had better equipment and lots more experience than I had. I told them what I had done and suspected the furnace. Could they find the leak and fix it? They said they could and sent a tech out to me. I did the plastic thing for him. The tech did what I had done, put a guage on the line and verified that there was a leak, somewhere. I asked if he could take the furnace apart to find the leak. He wasn't certified to do work on appliances. So 1 hour and $275 later, he told me exactly what I already knew and left.
Any help/advice on finding a small leak in an Attwood furnace?
Any RV repair in SE FL that I can get to help? I've called Palm Beach RV and they only install new. They don't fix.

[Paul O.]

Based on my experience with my 2004 Scamp, I would say you do not have much to loose by starting to take the furnace apart yourself and sniffing with the sensor to find the leak. If you can put it back together, after fixing or replacing the part, that is great. If not, install the replacement. In 20 years many camper appliances are on borrowed time.

[kevin57]

An “rv tech” that doesn’t work on appliances? How is that so post to work? Has even being an rv tech expectations and quality gone down that much too? Or is it that it is still under warranty and you will want someone that can warranty the repair? Either the gas line connection is bad to the gas valve or the gas valve needs replaced because it is not properly stopping gas flow when off sounds like to me.

[mariaandskip]

It's a 2005 Bigfoot so no warranty.
I tried spraying soapy water on joints but no bubbles. Apparently it is a very slow leak. I only get a reading on the sniffer if I put plastic over the furnace access door and wait 10 minutes. I do get a reading with the plastic off if I stick the sniffer up inside the exhaust tube of the furnace.
I have to see if I can cap off the line to just the furnace. If that stops the leak then I'm sure it's the furnace.

[Nick Loy]

I have no real answer but ... I assume the furnace was off during your testing. It could be the closed solenoid valve has a tiny leak . (It no longer perfectly closes.)

Nick

[computerspook]

Originally Posted by Nick Loy

I have no real answer but ... I assume the furnace was off during your testing. It could be the closed solenoid valve has a tiny leak . (It no longer perfectly closes.)

Nick

The thing is that it sounds like the alarm is in the camper living space. A failing solenoid valve is very possible. BUT!!! it should leak into the outside via the outlet for the burned gases or maybe the inlet in some cases. But it should not be leaking into the living space.


I would try maybe soaping all of the lines near the furnace not just the joints. Maybe something has causes a hole in one.

[cwall59]

I had something similar on my 5thwheel and it turned out to be a bad sensor. I called the manufacturer of the sensor and they said it had a 5year warranty. It was only 2 years old and they sent me another one . This was after doing checks to make sure I didn’t have a leak or sensor wasn’t dirty or have an insect in it . If you are using an electronic leak detector some of them will read falsely if certain insulation is nearby.

[kevin57]

That’s true could be a faulty gas detector that led you to find a second problem where your furnace gas valve is faulty. See, even broken it does it’s job! And that’s really weird the “rv tech” does not work on appliances. The person should be called and RV not an RV Tech.

[mariaandskip]

The RV "tech" did do a pressure test and it did show a slow leak "some where".
I already knew that.
Open the door and window. Turn off gas at the tank. Wait 10 minutes then hold a lighter to a stove burner. If the lines did not leak there will be enough pressure and gas in the lines for a short bit of flame. There was no flame, this was verified by the "tech"
I guess my next move is to check the selenoid although I sprayed nearly everything with soapy water.
I know that my sensor is very sensitive. If I bring a can of WD40 into the trailer, not use it but just to set it in there, it will set the sensor off, put the can outside and the sensor is quiet.
Now I just have to figure out how to remove the selenoid. Maybe I'll start the and stop the furnace a few times first as it hasn't been used in years.

[cwall59]

One place to look for a leak is if they used a copper line to make a connection. Cooper lines in residential and commercial construction hasn’t been allowed in years . Cooper to steel will sometimes start leaking after some time due to corrosion or loose connection cause by dis-similar metals ( Cooper to steel ) .

[redbarron55]

Try replacing the leak detector as they will do that exact thing when the detector gets old.
I had one in a 5th wheel that did exactly that.

[Jim Bennett]

I too think the best thing would be to replace the propane sensor. They are only good for 5 years and cheap to buy.

[mariaandskip]

A drop in pressure was detected. The propane detector is less than 2 years old. Is there a better leak detector than soapy water

[C&G in FL]

Originally Posted by mariaandskip

A drop in pressure was detected. The propane detector is less than 2 years old. Is there a better leak detector than soapy water

I would be curious as to how the drop in pressure was detected. Pressure in the propane tank is high, but the regulator reduces it to 11-inches of water column, or approximately 1 psi. On systems using two tanks with a change over regulator, there (typically) is an indicator which shows when there is no pressure, i.e., an empty tank. I thought i had a slight propane leak at one point because a day after halving off the empty tank the indicator would go from green to red. Ultimately, I replaced the regulator and when the tank was valved off, this ceased happening. I chalked it up to a finicky indicator. The replacement regulator is now 5 years old (same brand) and has started doing the same thing. Propane contains a lot of impurities; I suspect impurities may be causing problems with the indicator because I weighed a tank after it was valved off, and reinstalled it, turning the valve on. Approximately 6 months later, the indicator was still green. I then valved it off and weighed it, and it was virtually the same weight as it was when first weighed.
I would also comment on propane detectors. Yes, they are generally warranted for 5 years. I kept getting false alarms, even when the propane tanks were valved off. You haven’t really experienced RVing until you have been ripped from sleep at 2:00 or 3:00 am three mornings in a row. I finally determined that the alarm was being caused by minute amounts of hydrogen from battery off-gassing in a poorly vented internal battery box with the propane detector installed within 18-inches of the battery box. I ended up putting a switch on the alarm to quickly silence it and boxed in the back side of the detector to “isolate” it from the battery box. It solved the problem. I have since switched to lithium batteries; they do not off-gas. But there is a misconception that propane detectors are only “good” for 5 years. I had a long conversation with the owner/CEO of Saf-T-Alert when I was experiencing the false alarms. I told him I had installed a switch against alarm packaging instructions and that I simply looked at the alarm to make sure it was on when we were on the road. He told me that the material in the sensor only deteriorated when the alarm was powered on, and that cutting power when in storage would greatly increase the life of the propane detector. My unnessarily replaced detector, now on an on/off switch is 8 years old and has not started “end-of-life” chirping when powered on.

[computerspook]

Originally Posted by C&G in FL

I would be curious as to how the drop in pressure was detected. Pressure in the propane tank is high, but the regulator reduces it to 11-inches of water column, or approximately 1 psi. On systems using two tanks with a change over regulator, there (typically) is an indicator which shows when there is no pressure, i.e., an empty tank. I thought i had a slight propane leak at one point because a day after halving off the empty tank the indicator would go from green to red. Ultimately, I replaced the regulator and when the tank was valved off, this ceased happening. I chalked it up to a finicky indicator. The replacement regulator is now 5 years old (same brand) and has started doing the same thing. Propane contains a lot of impurities; I suspect impurities may be causing problems with the indicator because I weighed a tank after it was valved off, and reinstalled it, turning the valve on. Approximately 6 months later, the indicator was still green. I then valved it off and weighed it, and it was virtually the same weight as it was when first weighed.
I would also comment on propane detectors. Yes, they are generally warranted for 5 years. I kept getting false alarms, even when the propane tanks were valved off. You haven’t really experienced RVing until you have been ripped from sleep at 2:00 or 3:00 am three mornings in a row. I finally determined that the alarm was being caused by minute amounts of hydrogen from battery off-gassing in a poorly vented internal battery box with the propane detector installed within 18-inches of the battery box. I ended up putting a switch on the alarm to quickly silence it and boxed in the back side of the detector to “isolate” it from the battery box. It solved the problem. I have since switched to lithium batteries; they do not off-gas. But there is a misconception that propane detectors are only “good” for 5 years. I had a long conversation with the owner/CEO of Saf-T-Alert when I was experiencing the false alarms. I told him I had installed a switch against alarm packaging instructions and that I simply looked at the alarm to make sure it was on when we were on the road. He told me that the material in the sensor only deteriorated when the alarm was powered on, and that cutting power when in storage would greatly increase the life of the propane detector. My unnessarily replaced detector, now on an on/off switch is 8 years old and has not started “end-of-life” chirping when powered on.

They said how this pressure was tested. They turned on the gas and ran the stove, once the inside was vented. They then turned off the stove and then turned off the gas at the tanks. They then waited and tried the stove again to see if it still had pressure. Actually this is a good thing to check in general every once in a while.

[mariaandskip]

Thanks for answering for me as to my pressure testing method.
I think that I'm safe in assuming that my propane detector works because it only goes off if the door and windows are closed and the propane is turned on at the tank. Turn off the valve, open the door, turn on a fan and the detector goes silent.

[mariaandskip]

I found that if I stick the sniffer probe into the exhaust of the furnace I get a high reading.......solenoid?

[computerspook]

Originally Posted by mariaandskip

I found that if I stick the sniffer probe into the exhaust of the furnace I get a high reading.......solenoid?

Good guess. Other choices though would that be a good one to start with