Hello,

I have a 10 month old tankless water heater. Sometimes when I turn the hot water on from anywhere in the house, it makes a loud grinding noise for a few minutes and then stops. I don't think it should do this. Do you have any idea of what it might be?

Sometimes when I turn the hot water on from anywhere in the house, it makes a loud grinding noise for a few minutes and then stops. Is your tankless gas or electric? Does any air come out of the hot water faucet when this happens? Tom

My tankless water heater is gas. There is no air coming out of the faucet.

Thanks.

This sound. Does it sound like metal grinding or is it more of a popping snapping sound? Let me know. Tom

Its more like metal grinding. It isn't a popping sound.

Thanks.

This could be the draft inducer motor or wheel making noise. If unit is only ten months old, I would get installer back to look at it, it should be under warranty. Good luck and please let us know how things turn out.

Just curious, other than this problem, have you been happy with the tankless? What brand is it? Any pros or cons you would like to mention.

Its is a Mobius T-M1. So far it has been good. My water bill the last few months keeps going up so will see. My neighbor has one too and her water bill was like $400 but they came and installed a new meter so it should help with the bill. Thanks for your help.

A small increase is water usage is normal for tankless water heaters, as it takes a period to heat the water, so you will run more water to get hot water at tap(unless recirp pump is installed on heater). Have you noticed a savings on gas?

You won't see too much changes in water bill. Your usage will be more-less the same. It is the gas bill that should be going down.