Tracking down source of gas odor...

[dpb]

Small NG heater in the well house. When operating, on occasion get an odor of gas but have had no success at all in finding source of any leak.

Interesting discovery--installed new pilot and safety control valve last year owing to two things--old one had a "wild" pilot that is, of course, inherently unsafe as well as now no longer legal and the final straw was that the old pilot assembly had eroded to point didn't have good flame. Anyway, did that last spring after last of cold weather was open.

The new TC works w/ the safety valve now just peachy keen--went out there the other day after a really windy day (this is SW KS, after all) and the pilot had been blown out. The safety valve had closed since TC was cold w/o the pilot light to keep it warm and there was _no_ odor. This pretty much proves that any leak cannot be in the piping up to the control valve or even as we had thought perhaps in the service line and coming up through the small hole in the slab where the pump entrance line from the well to the tank comes through thought perhaps a pinhole there might let gas migrate along the pipe and follow it up. This result indicates no leaks there.

So, I relit the pilot and again there is now some small odor -- it's not terribly strong but nowhere can I find any leak in the connection from the valve outlet to the pilot/burner...soapy solutions on all the connections show nothing, getting down on belly and sniffing around can find no location w/ any stronger odor. Anybody got any ideas as to how/where this might be traced down????

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[Jim Elbrecht]

I wouldn't trust my nose on that one. I'll bet the well house is too small for there to be enough O2 for the heater.

I'd put an explosive gas/CO detector out there and make sure I wasn't about to blow up the well house. [you'd have to spend some time out there to be harmed by CO-- but keep in mind it *is* accumulative]

Jim

[Zz Yzx]

Your gas supplier should provide the leak detection service for free. They have the training and tools.

I'd call them out.

[dpb]

That's actually not a bad thought, Jim...it is only 8x10 or somesuch and is fairly tight being block. Hadn't thought about it possibly being that but that it doesn't really smell like pure odorant/gas is probably a clue. Of course, store bulk oil and chemical in there too because it's the one place that is kept above freezing outside the house so there's a conflicting set of both petroleum and other chemical odor sources as well (pun not intended; the well is no longer in the well house; only the pressure pump/controls as the well around which it was built didn't last very long).

I really don't think it's close to getting to an explosive mixture level, though; this heater has been out there (w/ the wild pilot until this year, even, so I'm sure there have been times when the pilot went out and it still didn't blow even w/ that uncontrolled source) since the early 60s. If it were that high a concentration it would have done it long ago. It's just annoying and leaves one w/ the feel of mayhaps just... :( I'd like to cure it if I can figure out what the cure is--and you may have just hit upon it.

I'll think about how I might introduce some combustion air--leaving one of the jalousie windows ajar would do it I suppose but is a little hard on the thermal envelope. :)

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[dpb]

They've been out a couple of times w/ no more luck than I on pinpointing anything, unfortunately.

[Retired]

Possible dumb question here. Does this heater have an exhaust vent/flue/chimney; or is it a "flueless" space heater ??

Can you post a pic ??

[dpb]

On 12/17/2012 4:54 PM, Retired wrote: ...

Yes, no, no (that is, could but not going to as don't think it's of any pertinence at the moment, ...) It was out entirely while retrofitting the new pilot assembly and installing the safety valve so know the flue isn't plugged 'cuz had it down...

Not bad question though, but down the wrong track methinks... :)

[dpb]

...

...

OK, I did open one just a wee crack this evening...will see how it smells in the morning...

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[Zz Yzx]

On rare occassion, I get a slight whiff of natural gas odor (actually, it's a mercaptin chemical that's added to the natural gas; skunk scent is also a mercaptan) from my water heater closet. Same deal: can't find it, gas comapny can't find it, it goes away.

[clare]

What kind of burner??? Sometimes if it is a perforated tube or cast iron burner a couple of the holes do not burn properly (sometimes a few blow out due to air movement - common in places like rural SW Kansas) and the unburned gas smells the place up.

[dpb]

On 12/17/2012 7:47 PM, [e-mail] wrote: ...

That's not a bad thing to check on--thanks.

It is a _very_ old heater; I remember it as a kid was in the bathroom of the house before folks added the central air/remodeled and that would have been early '50s. I suspect it was installed when they moved the house from the site west of town that became the Army air base (B-24 commander training base) during the war in spring '43...altho it might have not been until after the war rationing was over. So, I know it's at least 60 and may be nearly 10 yr older than that.

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[bob haller]

you can put a plumbers P trap thru the wall.it wil allow makeup air entry but prevent gross loss of warmth

[homeowner]

There are different types of gas. What kind are you smelling? Maybe you just eat too many beans!!! In a small shed like that, it will be much more noticable. :)

[dpb]

...

Looked up Code reqm'ts for 100% combustion air internal--for a normally tight dwelling it says 50 cu-ft/1000 Btu; now I'm left wondering what is the capacity of this little heater? Got any ideas on how to guesstimate what that might be? It's a single row of burners roughly a foot long I'm guessing; I'll have to go take more exact measurements. AFAICT there's no ratings on it that are legible any longer, anyways...

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[dpb]

Well, I didn't look in right place while laying on my belly on the floor of the pump house... :) -- the getting up from which isn't as easy as it used to be, either. :(

Anyway, the dimensions are bigger than I think--it's 8x14.5x7.5 interior which is just under 900 cu-ft and the input is 16000 Btu/hr. That's just a little above the 800 cu-ft for inside air ratio by the Code table I found so guess that it's a little smelly might not be surprising.

The tiny crack on the window didn't really seem to make much difference overnight last night but it was almost dead calm and I did leave it open only a very small amount so wasn't much air circulation certainly.

I did really look at the flame down the burners just now and they all appear to be firing fully and not intermittently w/ a nice blue flame so I still have no real answer other than the air supply. I do need to get on the roof and be double-sure the rain cap/wind diverter are open -- got to thinking I know about the flue from when pulled it last spring but I didn't go up top then.

Anyway, there is a CO monitor upstairs, guess I will take it out there and plug it in the wall and see if it reads anything significant...

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[PeterD]

check your underpants.