Combustible gas detected from sink drain

I know sewage gases can set off the combustible gas detector but these readings are really high and was wondering if this is something my client should be concerned with?
Does anyone know what causes this to happen?

Is that drain a garbage disposal?

Can you smell anything? If not I wouldn’t worry about it.

Just curious, what made you test the kitchen sink for combustible gas??

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It is the garbage disposal, but it was doing it from both sides of the sink

The homeowner said she thought she smell gas for the drains

My guess is it’s most likely decaying food in the disposal, have them clean the disposal.

best way to clean a garbage disposal - Google Search


Sewer gas may contain methane’


Are they not connected under the sink?

Was it the smell of natural gas? Or something else?

I did not smell anything.

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Interesting. I like the methane theory.

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Baking soda works fine for cleaning the disposal. Those gas detectors get plenty of false positives - that’s why I don’t use them. Save your money and buy something useful like a personal CO detector. Don’t know what brand - consult your local fire department, see what they’re using.

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So what do you know about your tester?