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methane gas smell coming from hot water hearter? Answered

went to take a shower tonight and noticed when hot water heater turned on this smell came out. i have rc cars that run on nitro methane and it was almost the same exact smell as what comes out of the exhaust it burned my nose and lungs  the hot water heater runs off gas and wasnt a gas smell anyidea what this could be ? 


Where are you and what is your water source?

When I lived on the farm just out side of town this would happen to our well water once in a while and when the water filters or the water heater needed replacing.

It also happens when excess sulphur leched into the well water.

If there is no gas leak it is quite possible that the insulation is overheating somewhere, at least it would explain the weird smell.
Certain plasics give out all sorts of chemical smells depending on what temp they are exposed to.
If you are renting inform you agent or landlord right away and try not to use the heater until it is properly checked out.
If you own it you can try to check for burnt or mislodged insulation if the cover can be removed safely - AFTER turning the gas off!
But I would recommend to call a professional either way just to be on the safe side of things.

Depending where you are in the world, think twice before removing the cover - in some places it just invalidates your home or appliance insurance, but in the UK it is an offence to work on gas appliances without the appropriate training and certification (know as being Gas Safe Registered - if you hire somebody claiming to be CORGI registered, that qualification is no longer recognised, and they are working illegally).

Its isn't (or wasn't) illegal to work on your own gas equipment though, it IS illegal to work on someone else's..

The 2013 regulations mean that if you are paid for work on gas, you must be fully trained and Gas Safe registered. If you are not being paid, you do not need to be Gas Safe registered, but you must have undertaken all the training you need to do to get registered:

The regulations are quoted in this consultation document:


Work in relation to a gas fitting
30 For the purposes of these Regulations, “work” includes do-it-yourself activities, work undertaken as a favour for friends and relatives, and work for which there is no expectation of reward or gain, eg voluntary activity for charities. This means that anyone carrying out such work must have the necessary competence, as required by regulation 3(1).

And Regulation 3(1) says

Gas work should not be undertaken except:
a) by a person who has successfully completed an industry recognised training course followed by assessment of competence. Training that leads to assessment of competence in safe gas work must be recognised by the industry’s Standards Setting Authority. or
b) in the case of a previously Registered person, they have proved competence through a Certification Scheme. or
c) for those working at premises that fall outside the scope of the Regulations (see regulation 2(4) and associated guidance), by a person who has successfully completed an industry recognised training course followed by assessment of competence.
61 Training should be of a standard to enable a gas engineer to achieve competence in the safe installation, purging, commissioning, testing, servicing, maintenance, repair, disconnection, modification and dismantling, of the gas systems, fittings and appliances with which they are working. This should include an adequate knowledge of associated services, such as water and electricity, of the dangers they may give rise to and the precautions to take.

You might have a cow that is stuck in your water heater, You can identify this by checking if there is a moo every couple minutes...

Well, That technically is somehow possible :)

I'd be worried that it might be something in the tap water.

Try putting a sample of your cold tap water in pan and heating it on the stove, for to observe if you can make the cold water produce the same smell, just by adding heat to it.

If you can make the water turn stinky, just by adding heat, then it's not a problem with the water heater.

On a whim, I looked up nitromethane in the Wikipedia,


Not sure how much help the great Wiki is going to be for identifying chemicals by smell, but at least now I know how to spell it. ;-P It's all one word.

If you have neighbors you can talk to, you might sort of discreetly ask if they have smelled anything in their water.

It's a topic that can kind of freak people out, I mean, the suggestion that there might be something stinky in the water. That's why, when you ask about their water, you mention that you smelled something in your hot water, but you're not sure if it's the water itself or something screwed up with your water heater.

I mean, if it truly is the water heater causing the stink, they'll be releived to know this.