Ask Your Question

Angie's List Answers is the trusted spot to ask home improvement and health questions and get answers from service companies, health providers and consumers. For ratings and reviews on companies in your area, search Angie's List.

Top 30 Days Experts
Rank Leader Points*
1 kstreett 240
2 Guest_9020487 110
3 Guest_9190926 105
4 GoldenKid 100
5 ahowell 95
6 KnowledgeBase 95
7 skbloom 80
8 Guest_98024861 70
9 Guest_9311297 70
10 Guest_9400529 70

*Updates every 4 hours

Browse Projects By Category

Question DetailsAsked on 5/7/2011

Smell gas coming from my tankless water heater

I have a Noritz 841MC tankless water heater. It was professionally installed by a local contractor. The unit vents a foot or so above the ground to the outside between my office and my daughter's bedroom. We smell gas if the water is used for a short time (hand washing, ex). I have had the fire dept. out to check out the problem. They said it was incomplete combustion coming from the water heater. I have had the original installer, 2 Noritz reps, and a Noritz technician out to assess the problem. Nothing has been resolved. Noritz says the unit works correctly. Any input?

Do you have the same question? Follow this Question

2 Answers


Noritz is an good brand. Did any one use a gas detector to see if there was leaking around fittings? If they did and you (ONLY) smell gas at the times of short run and no other time, it would seem to be an accurate assesment that it is uncombusted fuel from the short run. Try it with your gas range, turn it on and immediately off, you will probably smell some unused gas.

Answered 8 years ago by Cline1


Gas appliances, when they fire up, commonly emit a few seconds of unburned gas along with the initial combustion products - so you will smell just a short burst of gas smell coming out the flue. Stand outside by the vent and have someone use some hot water and see if the smell actually coming out of the vent is just for a few seconds (not more than 5 or so) - if so, then maybe you need to consider getting the vent relocated or putting a drip tee on it and a vertical extension (if allowed for your unit) to get the discharge point away from your windows, because the gas odorant can linger (and is supposed to) for many minutes.

Codes vary by locale, but typically a combustion gas flue (which this is) has to be at least 3 to 5 feet (sideways or below) and from 1 to 3 feet (if above) from an opening window or other type of air intake. If yours does not meet your local code (check with your building department on local code requirement) then it was not properly installed and I would call the installer back to fix it (for free).

Answered 6 years ago by LCD

Related Questions

Terms Of Use
Privacy Policy