On Demand Hot water heater next to service panel

I just inspected a home with an on demand hot water heater in a small 3x5 utility closet. The venting was touching combustibles going through the ceiling. This is obviously an issue.
My concern was that the unit though authorized for indoor use and clearances to combustibles around the unit are met, it is littoraly only 12-14” from the main electrical panel. There is no ventilation in this closet.
Hypothetically speaking if there were a gas leak and an arc from the panel this could be a dangerous thing. My question is, does anyone know clearances to electrical sources and gas appliances and were I might be able to look it up? How about venting? I was not sure exactly. Thank you all, I hope your Thanksgiving Day was a blessed one to be remembered!

There is 30" of working space required in front of the electrical panel. The space could be in either direction. Could be 5 inches on one side and 10" on the other (the rest made up by the panel), or measured from the center of the panel. Then there are clearances by the water heater manufacturer… Otherwise it should be fine. Regarding the venting, where is the unit taking combustion air? You need make up air for gas burners either directly from outside, from inside if the open space is large enough, or brought in from outside by ducts, or opening in the door (unless in bedroom).

Where is the closet located, post pics of the installation. I recommend brushing up on inspection of water heaters/boilers/furnaces that rely on fossil fuels. These items are covered in detail in Nachi courses.

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You can imagine all sorts of hypotheticals for every system in a house.
You don’t provide any details on the equipment, so hopefully you recorded the data and can review the requirements for that model.

I recommend you stick to what’s factual, specified, and prescribed (manufacturers install guides, codes, etc.)


Yes siree, I agree with Dominic.

Thanks guys . It is a Noritz N-063 indoor /outdoor unit and clearances seem to be met but there are some ventilation issues. However with this type of vent stack I believe fresh air and exhaust is in the same vent. So maybe it’s a non issue . The 30” in front of electrical I do t think is an issue as when the door to the closet is opened you have it.
I was more concerned about the possibility of of gas ignition. The closet is in a bedroom so more caution. I am going to try and post a pic. Thanks for the advice.

Not in Vicinity of Easily Ignitible Material. Overcurrent
devices shall not be located in the vicinity of easily
ignitible material, such as in clothes closets.

Not an issue, the heater itself has plenty of electronics inside that can spark… the unit is not supposed to leak gas. If it does, the electrical panel is going to be least of the concern. Such gas clearances are typically around gas vents (that emit unburned gas). From the looks of it, this is not a direct-vent unit, the make up air must be provided. The closet must be 100% sealed from the bedroom, the door should be self-closing, check the page 14 of the manual. Maybe you missed the make up air vents?


It’s a utility, not a clothes closet. Shows us code where the panel cannot be near gas water heater.

I always used to Google the installation instruction if they weren’t handy on site and I think these are those:




OP said bedroom closet. I quoted the NEC in my answer. It’s in 240.24.

are you always confused? he clearly said it’s a utility closet: “water heater in a small 3x5 utility closet.”

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Was this room converted into a bedroom?

Same bullshit different day :face_with_raised_eyebrow:

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I’ll grab a beer while you read.

If you spent your time helping people rather than attacking me maybe you could help the OP.

I’m helping members to beware of you, a non-member jackass… … … …


first true thing that I have seen you post


LOL!!! :rofl:


Thanks guys. I am seeing enough wrong with the fire stop and a comment about 4’ clearance from “any” door as well as the 4” slope. I already recommended evaluation of the system but i wanted to help the client more with solid facts. I hope it gets a bit easier but i reviewed this manual when writing the report late in the eavning and I did not catch these things but was stuck on the electrical and ventilation. After just checking clearances. Thanks for the replies they all helped


He stated that it’s a utility closet in a bedroom.