Prestige Excellence leaking propane

oak

A TT certified tech spent 6 hours servicing my boiler yesterday: new igniter, new temp sensor, tightened some leaky supply side fittings, fine tuned the unit, adjusted the DHW temp, etc). But after all that, the propane smell returned.

The leak does not show itself using a spray-on leak detector. So we used a gas sensor but it was inconclusive; we could not replicate the leak pattern. It seems to happen when the boiler is not firing (after the tech went home)

The only odd spot the gas sensor reacted to was around the gas valve/solenoid (part #5 in my manual); but not continuilously.

The leak even happened after (upon TT's advice) I shut off the boiler and closed the main gas line. It leaked periodically for 2 days after that.

I read on line that changing the solenoid/gas valve sometimes corrects this problem.

plumbgod

is there a back draft in the venture?

Tim McElwain

Have your propane supplier conduct a system leak test using a pressure gauge.

delta T

Have you checked (and I mean really really checked) ALL of the gas fitwwtings in the room? If the unit had its gas supply turned off and you still smelled it, then it may not be the unit. Then again it may be. Propane smell lingers for a long time.

Some things to consider:

Is the combustion air termination outside anywhere near your LP tank, 2nd stage regulator, any gas piping at all? The smell could be coming from there, especially regulators. They have vents on them that may realease a small amount of gas periodically.

Any old style gas shutoffs with a little ear instead of a handle?
like this:

http://www.google.com/imgres?imgurl=http://www.diychatroom.com/attachments/f7/53954d1342141351-leaking-ball-valve-gas-line-112-003.jpg&imgrefurl=http://www.diychatroom.com/f7/leaking-ball-valve-gas-line-150061/&h=154&w=174&tbnid=4R4ANKShqd7tVM:&docid=2UXiMwocY9xTtM&ei=6pPOVcS2Hs-VyAS6pry4BA&tbm=isch&ved=0CCkQMygMMAxqFQoTCMTTk4T2qccCFc8KkgodOhMPRw

Those seal with a greased brass against brass seal that needs to be serviced every now and then by re-greasing and tightening (though it is more economical most of the time to replace the valve).

How was the gas meter inconclusive, did it detect gas but was unable to pinpoint the source or did it not really detect any gas? I almost never use a gas meter to find leaks. Don't get me wrong, they have their uses, but I feel that sometimes they are too touchy and are bad at identifiing specific leak sources. Using a good bubble solution is almost always faster IMHO. Dish soap and water is not a good leak detector. While it may find big leaks, it will dry up and evaporate before it finds the really small leaks. I recommend using this stuff, though any good bubble leak loacting fluid will work:

http://www.amazon.com/Nu-Calgon-4184-24-Fluorescent-Leak-Detector-Qt/dp/B0056BOUHM

It will stay in place for a long long time withouth evaporating, it forms and holds bubbles for a very long time, and allows you to see small leaks easily if you wait long enough. I have seen this stuff show a very small leak with a big blob of bubbles (size of a golf ball) after I sprayed it on a Thursday and was back to the job on Monday to check my radiant tubing. That leak was so small that the drop in the pressure gauge over that time period was less than .5 psi. It works.

I have been in several situations like this where the apperance of an intermittant "gas leak" confounded me and several others for days and days until we found the evaporated floor drain under the water heater, dead mouse in the bathroom fan vent (true story!), or other smelly thing mistakenly thought (by me too) to be a gas or propane leak.

The only way to solve these is to start eliminating things one at a time. Thouroughly check all piping that you can get to with bubble solution, or as Tim says have your supplier perform a leak check. dump water down any floor drains, tubs, sinks, clothes washer boxes, etc that do not get used frequently. Check under cupboards, in corners, places where you could suspect a small dead rodent of hiding from view. I suspect after looking for six hours for a leak on the unit, it may not be the unit (though of course it may be). Keep looking in different places and eventually you will find it.w

Best of luck!