Heater Gas Smell

[Cayman]

We recently moved into a new house that had a hot tub and heater, which we have never had before. We have used the hot tub several times and everything seemed normal until last night. Last night we smelled gas on the patio and while in the hot tub.

Is it normal to smell gas while running the hot tub?

Thank you.

 

[Toxophilite]

No, it's not a normal thing, but could be just a temporary thing if you have not noticed it before. Barring smelling any leak with unit not running and carefully inspecting that way first by using your nose, it can be a sign of incomplete combustion. Many things can cause that, but if it only happened once it could have been a high wind condition and downdraft over the exhaust port. I would rule nothing out, test it by running it and close inspection. If in doubt, always call a service tech to come do an inspection, which is not unlike having your home furnace annually inspected.

 

[Cayman]

Thank you for your reply. I do not smell gas when the heater is not running, before or after we smelled it. It was a little breezy last night and from a different direction, but if you shouldn’t smell gas at all, that shouldn’t matter, correct?

 

[setsailsoon]

If you smell gas when the heater is running that's not normal except briefly when it goes through the start cycle. "When in doubt get it checked out"

 

[Cayman]

I’m running it again right now to see if it smells like gas again. I did smell gas right when it fired up (standing by the heater itself), but then it went away. I’m going to go inside for a bit and then come back out and to see if I smell it then, last we did last night.

 

[JamesW]

Heater model number and age?

Natural gas or propane?

Do you have pictures?

Maybe a vented regulator?

You can have an HVAC or gas plumber contractor come out with a sniffer that detects gas.

They can also use a soap that can detect leaks.

 

[mknauss]

Be aware that your other gas fired heater appliances (furnace, water heater, etc) vent far away from your nose. The mercaptan added to the gas so you can smell it does not combust as readily as the natural gas compounds. So your pool heater exhaust is right at your nose. So at startup, smelling some odorant is normal. But once running, the smell should dissipate, but combustion gases still have an odor.

But do not hesitate to have a licensed technician check this out if you have concerns.

 

[Cayman]

Ok I just went onto patio and didn’t smell anything; on the patio or by the heater. My guess is the initial gas small drifted into the cage/patio area and that’s what we kept smelling last night.

 

[JamesW]

HOME-FLEX Electronic Gas Leak Detector 11-810-001 - The Home Depot

The HOME-FLEX Electronic leak detector is designed to detect even small gas leaks. Built-in microprocessor easily detects natural, liquid propane, butane and methane gases. Red and yellow lights illuminate

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UEi Test Instruments Combustible Gas Leak Detector CD100A - The Home Depot

The CD100A is the service persons tool designed to detect combustible gas leaks in residential and small commercial applications. Semiconductor sensor responds instantaneously to all combustible gases.

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TRIPLETT:Triplett Combustible Gas Detector with Flex Gooseneck GSM100 - The Home Depot

The Triplett Model GSM100 Combustible Gas Detector identifies the presence of combustible gases such as Methane, Hydrogen, Carbon Monoxide, Propane, Ethylene, Ethane, Hexane, Benzene, Iso-Butane, Ethanol,

www.homedepot.com

 

[setsailsoon]

Problem with gas smells is they can be variable for many ordinary reasons like temp changes, pipe load changes etc. This is a very good reason to be sure somebody uses a sniffer as James suggests. Bubble tests are good and most commonly used. The problem is a very slow leak or variable leak or difficult to see location or windy conditions can make this less reliable. Sniffers seem to pick up the most tiny leak very reliably. Safety policy at all the industrial plants I've worked in require both or a sniffer. Never just a bubble test. Below is an example valve that I've kept around for years to explain this whole concept. Gas was smelled "sometimes but not always". The first views are the outside of the valve. No visible source of leak right? No bubbles presented but sniffer went nuts with the loud squealing screech. Looking at the bottom view after the valve was removed you can clearly see a crack in the threads on one side that go all the way through the valve.

I hope this is helpful.

Chris

 

[ajw22]

What model heater are we discussing? I don't see one listed in your signature.

Post pics of the heater showing the gas line into it.

 

[tgrinchy]

Any gas regulators close to the heater? Those tend to vent at times which I’ve noticed sporadic gas smells as well.

 

[Cayman]

Thanks for all of the help. I believe this was due to the wind direction at startup. It blew the initial unburned gas toward the spa, and it appears the cage kind of held it in with the wind. We’ve smelled nothing since, though winds shift the same direction this weekend, so I’ll try again to duplicate the issue.

 

[guinness]

I've used this Gas Leak Detector with adjustable sensitivity to test for both natural gas and propane and it does work. You will want to test around your heater when it's still outside. It would probably alarm around the vent area during the startup cycle.