Tankless water heater concern

Hello folks. I inspected a home with a tankless water heater installed in a garage. The installation looked like a DIY type of job but everything functioned properly and I had no gas leak or CO inside the space and the unit was vented to the exterior of the garage through the roof.
My client, after living in the home for two months, was dissatisfied with the amount of hot water the unit provided and sought the expertise of a plumber to install a larger system to meet her demands. The plumber advised that the current arrangement is dangerous and that she needs a complete re-installation of the system. My client is now asking that I foot the bill of the entire project as I should have known that the system was not permitted (she thinks I should have gone to the authority having jurisdiction and determined if a permit had been pulled) and that the arrangement is dangerous.
I do concede that I should have mentioned that the unit is typically installed on the exterior and should have recommended that the buyer should seek further information from the seller regarding the installation.
Am I totally on the hook for this? Any guidance is greatly appreciated.

Do you have pictures? Why was it dangerous? I see these in basements often. Does your agreement cover the fact that you are not pulling permits?

Mine says the following: “NO search or check of municipal records or property boundaries (land survey) is included.”

I have never seen one installed on the exterior here…where are You located ?

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I would first seek written explanation from the plumber why he believes it is “unsafe” Gas water heaters are installed inside a garage all the time. You just have to follow certain safety requirements. The plumber could just want more $$ out of the client by doing complete reinstall.


I’m in NC and have seen them on the exterior a few times…so that’s not so crazy around here. I do see gas water heaters in garages all the time!!! So i don’t know what exactly makes things dangerous. I do not have the verbiage in our PIA regarding permits…but will change that today!

The unit has a proper vent through the roof as well. I am about to call the plumber and get a letter stating why it is indeed unsafe. Thanks guys for helping!


NO! This is not proper or approved, that is homeowner special converted outdoor tankless unit to vent outside. Plumber is correct.


Well… looking at the photo I would have to agree with Simon.
Can’t understand how you would not be concerned with that installation.
Total FUBAR!


I was concerned and should’ve absolutely commented on the install…I just (foolishly) assumed it had been approved. When I checked for leaks and found none I thought we were good. Big time lesson learned! Outside of its unsightliness, I don’t see what is dangerous about the install.
Thanks again guys.

Not only shouldn’t you assume it has been approved, but even that process does not indicate correct installation.


Yup, you’re right.

Jason, you may want to take the InterNachi course on water heaters.
I hope you can come to an agreement with the home owner. Good Luck.

I will make it right with the homeowner…I screwed up. Thanks for the tip.


That’s not how things work… First and foremost, if I see a unit like an advanced tankless water heater not installed according to its manufacturer specs, it’s automatically wrong and requires further attention – an approval from higher authority who approved an alternative method of installation. To know what’s wrong, you need to know what’s right. If you wish to learn, look at the model of the unit in your pic, read its installation manual, read NFPA 54, take the nachi course on inspecting water heaters (like mentioned by Joseph).

This is an attempt to aim you into a direction of reading and learning that will hopefully keep you out of trouble in the future. Mistakes in HI could be costly enough to easily drive one out of business. GL.

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Hi Simon,
Thanks for your guidance. I do appreciate it. I read the installation manual earlier today. I know better than to not call it out and no excuse is even worth it…at the end of the day, I goofed and it’s gonna cost me some money…which hurts…but I’ve learned a valuable lesson, which is great.

I will read through the NFPA guide, I’m pretty familiar with NFPA.

I’m beside myself for not calling that out, but I will absolutely make things right with my client.

Thanks for reaching out. It means a lot to me that you’d take a moment to help me out. Have a wonderful day sir.

Edit: after reading NFPA 54, it’s pretty dog gone clear. Thanks again all.


Isn’t that the real estate agent’s job? Is their disclosure in your state?

In Ohio that is outside the ‘scope’ of a home inspection so if you were here I would say that you were not responsible for discovering what is probably a public record.

Maybe your state is the same?

You have no idea as to what you are talkin’ about …Huh?
Then please shut up…OK?

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Hey Roy;
You’re spot on about some things but you’re also a downer on most of what I see you write about. It seems like you go out of your way to get on people’s cases in a rude manner. I don’t know what cards were dealt in life to you but take a breath or two. And please respond tactfully to what is contributed here in the forum. Lighten up on yourself and others. I’m sure that you have much to contribute to CPI’s both established and just starting out. God bless you brother.


On demand water heaters are very different from what we think of as “standard tank style water heaters”.
Like in this instance, an exterior unit. This specific unit is only made to mount on the exterior of a house/building.
Other things that make them different, although more common than ever, is that most on demand water heaters (gas) fire at 199,000 BTU and often a homeowner will use a 1/2" gas line and wonder why things aren’t working properly.
Rheem, Rinnai and several others have a decent amount of online information available on what each manufacturer offers and how their water heater is applied. Just for your own info the max hot water output is 4.5 gallons per minute (GPM) on most units. Often a common complaint in larger households.

Read up on these water heaters…it will be worth your time.


IF you truly knew the man & his accomplishments, education, degrees & what’s inside his heart you would not have said that.

You have no idea as to what I’m doing . So! Mind your own business.