Tankless water heater freezing

35145 Views 26 Replies 12 Participants Last post by flashheatingand, Feb 28, 2018

Mitch M

Discussion Starter · Jan 6, 2010

I have a client who has a tankless water heater mounted on the exterior. He has had the pipes frozen over the last couple of nights because of the cold. The unit is mounted on the exterior wall and the pipes go in right at the unit into the interior. What can we do to keep them from freezing?

Thanks for your help.

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Leo G

· #2 · Jan 6, 2010

Put it on the inside of the house where it belongs.

Reactions: 1

KillerToiletSpider

· #3 · Jan 6, 2010

Mitch M said:
I have a client who has a tankless water heater mounted on the exterior. He has had the pipes frozen over the last couple of nights because of the cold. The unit is mounted on the exterior wall and the pipes go in right at the unit into the interior. What can we do to keep them from freezing?

Thanks for your help.

Build a heated shed around the water heater.

Cole82

· #4 · Jan 6, 2010

Tell them to shower more than once a week. The in/ex is letting cold air inside the water heater.

Guys I think it is inside the house but on an exterior wall.

genecarp

· #5 · Jan 6, 2010

KillerToiletSpider said:
Build a heated shed around the water heater.

Mind as well make it a 8' x 10' so at least they can store the lawn tools, maybe even put a sink in it, (with hot water), GMOD

Mitch M

Discussion Starter · #6 · Jan 6, 2010

Oh come on guys. It is one of those small tankless water heaters that is mounted on the outside wall. The pipes go into a heated space but the pipes directly on the outside freeze. They are wrapped with the foam insulation wraps but apparently it is not doing any good.

Leo G

· #7 · Jan 6, 2010

What makes you think I am kidding? A water heater in a freezing climate will have problems with the pipes freezing. What is the reason that it is mounted outside?

Mitch M

Discussion Starter · #8 · Jan 6, 2010

Leo G said:
What makes you think I am kidding? A water heater in a freezing climate will have problems with the pipes freezing. What is the reason that it is mounted outside?

I did not mount it. It is for one of my regular customers. It is like a lot of the ones that I have seen around. It is gas so it is vented. It is designed to be mounted outside. I think they just forgot to how to stop the frozen pipes.

Cole82

· #9 · Jan 6, 2010

I was wrong it is mounted outside...

Why would any body do such a thing in NY?

"T-K3-OS is ideal for warmer climates"

Leo G

· #10 · Jan 6, 2010

North Carolina.

Reactions: 2

painterman

· #11 · Jan 6, 2010

wrap the pipes with heat tape

Tinstaafl

· #12 · Jan 6, 2010

Yeah, it does freeze sometimes in NC. I've been there when there was freezing rain, and it ain't a pretty sight.

Probably the simplest quick fix would be heat tapes. Until you can get that set up, just have him let the water trickle (or even just a fast drip) at a HW faucet whenever the temps are low. As long as the water's moving even a little bit, it takes some pretty low temps to freeze it solid.

KillerToiletSpider

· #13 · Jan 6, 2010

Tinstaafl said:
Yeah, it does freeze sometimes in NC. I've been there when there was freezing rain, and it ain't a pretty sight.

Probably the simplest quick fix would be heat tapes. Until you can get that set up, just have him let the water trickle (or even just a fast drip) at a HW faucet whenever the temps are low. As long as the water's moving even a little bit, it takes some pretty low temps to freeze it solid.

That won't work with a tankless water heater.

Tinstaafl

· #14 · Jan 6, 2010

KillerToiletSpider said:
That won't work with a tankless water heater.

I was waiting for that! :thumbsup:

I admit I have no hands-on experience with them, so correct me if I'm wrong (like you wouldn't :laughing

. The idea is not to get it to fire up--I know you need significant flow for that. It's just to keep the water moving ever so slightly.

Shirley you aren't saying that a tankless won't allow you to run a trickle, as long as you don't care whether it's heated?

KillerToiletSpider

· #15 · Jan 6, 2010

Tinstaafl said:
I was waiting for that! :thumbsup:

I admit I have no hands-on experience with them, so correct me if I'm wrong (like you wouldn't :laughing. The idea is not to get it to fire up--I know you need significant flow for that. It's just to keep the water moving ever so slightly.

Shirley you aren't saying that a tankless won't allow you to run a trickle, as long as you don't care whether it's heated?

You'll foul up the flow sensor and send poor signals to the control panel, depending on the brand of tankless as to what gets screwed up from there, if it's a Bosch just write it off and start over again.

Tinstaafl

· #16 · Jan 6, 2010

All righty then. So actually, it would work; you'd just kill the heater. :blink:

That's totally astounding. I'm not doubting your word, but it sounds about on a par with "government intelligence" that any mfg would produce a unit so easily fouled up.

You just murdered any slight tickle of an urge I might have had to try one out.

Cole82

· #17 · Jan 6, 2010

Why do the Bosch ones slow the flow down so much?
I have installed 3 TL water heaters and 2 of the customers made me take them out. They were all bosch.

KillerToiletSpider

· #18 · Jan 6, 2010

Cole82 said:
Why do the Bosch ones slow the flow down so much?
I have installed 3 TL water heaters and 2 of the customers made me take them out. They were all bosch.

Because they are cheap, poorly engineered pieces of crap.

You get what you pay for.

Reactions: 2

ARealplumber

· #19 · Jan 6, 2010

KillerToiletSpider said:
You'll foul up the flow sensor and send poor signals to the control panel, depending on the brand of tankless as to what gets screwed up from there, if it's a Bosch just write it off and start over again.

All you would need to do is have one faucet running to keep water moving through the water heater. This would be no different than a few dripping faucets added up. I've never heard that letting afaucet drip or run alittle with a tankless would foul the flow sensor. What manufacturer's users guide says this?

KillerToiletSpider

· #20 · Jan 6, 2010

ARealplumber said:
All you would need to do is have one faucet running to keep water moving through the water heater. This would be no different than a few dripping faucets added up. I've never heard that letting afaucet drip or run alittle with a tankless would foul the flow sensor. What manufacturer's users guide says this?

None of them.

I used to work for a shop that was an authorized Bosch repair company though.

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