Question on tankless water heater

[Richard G.]

Son bought a gas Rinnai tankless water heater for his shop.
Has to be put on outside of wall in the weather or our propane supplier will not let him use it..
What keeps it from freezing and busting when not in use?
He does not have the gas hooked up yet.
That sucker is so full of sensors and wires that it looks like a spiderweb inside.
I think I would prefer a small tank type heater inside the shop where it would not freeze.
His shop is so well built and super insulated that here in NW SC, freezing would not be a problem.
Or he could put one in the office kitchen through the wall where he has heat all the time.
Richard in NW SC

 

[David G]

That is ridiculous

 

[J Hamilton]

I never heard of that, would it be for proper ventilation? You don't have to put a tank type gas water heater outside, just needs a vent. But I'm in a different state so building codes may be different.

 

[544hydro]

From their website it looks like some models can be mounted outside

Good news: The short answer is yes. Rinnai tankless water heaters feature freeze protection for outside temperatures as cold as -22 F (-30 C) for indoor models or as cold as -4 F (-20 C) for outdoor models when protected from direct wind exposure and as long as the appliance has both power and gas supply. The pipes feeding the unit must be heat-traced and insulated to provide the necessary freeze protection.

Rinnai strongly recommends the installation of an optional drain-down system on units installed outside in cold climates. Once installed, the system allows water inside the unit to drain out if theres a power and/or gas outage or a component failure. See the owners manual for optional drain-down system piping.

 

[504]

Without checking the manual,I would say it has a freeze proof feature. The flame comes on when it gets too cold. My first one did not do that and this new house was so airtight that the water heater would backdraft when the furnace came on. When that happened the water heater would freeze.(That is why I now have an electric one) Now I would have a freeze proof gas model.

 

[bc]

Not sure I've heard of a propane supplier doing that. Is it one that has to be vented? Is this a new tank the supplier put in to feed it as that is the only reason why I think they would care. If so, get the propane tank in and move the heater in side. Or use another supplier.

I've decided I'm not buy another water heater and will go tankless. Will pay extra for the one you don't have to vent unless it will hook up to the present vent.

 

[bamaray]

We have one inside our garage works great, son has one mounted outside it has froze here in Alabama. Daughter just built a house plumber insisted on mounting on outside, he got kicked off the job she found a plumber to mount it inside. Inside it only way to go they work great.

 

[wingnuttx]

I have gas tankless here at my Tx home but electric tankless at our camp in La. Both are mounted inside.

 

[David G]

These are sealed combustion.

 

[moresmoke]

If your house is that tight, you should have an outside air inlet to your furnace. No point in having the furnace struggling to pull cold air into the house.

 

[David G]

Agreed.

 

[Billy Shafer]

Could be a local code item. I found that on many generator installs.

 

[rustyfarmall]

Your propane supplier sounds like the one I used to have. Scared to death of their own shadow.

 

[mtf]

It needs to be placed closest to where it will be used the most!! It is recommended that exhaust pipe be less than 4 or 5 foot. I have one in the basement of my 2 year old house. Located directly below master bath, and close to kitchen as well. We love it.

 

[Steve@Advance]

What will he be using hot water for?

Some process that requires endless hot water? A shower? Hand washing?

Unless he needs endless hot water, tankless is a waste of money and maintenance expense.

The one I installed for a friend, was a total disappointment. There was no "blending" of just a little hot water. It required a minimum flow to make it come on, then that was too much, too hot when blended with summer water.

They may have improved them since then, but from what that one did, no way, no how!

 

[fixerupper]

That automatic drain system is on an old railroad diesel locomotive the local co-op used to switch cars. There no antifreeze in the engine just straight water. It is to be plugged in year round and if the power fails and the temp gets down to a certain level the water will dump out of the engine. This is probably 1950's or 1960's technology. Last winter someone forgot to plug it in after it was used the automatic water drain did not work. The locomotive is not being scrapped out because of it.

 

[fixerupper]

That automatic drain system is on an old railroad diesel locomotive the local co-op used to switch cars. There no antifreeze in the engine just straight water. It is to be plugged in year round and if the power fails and the temp gets down to a certain level the water will dump out of the engine. This is probably 1950's or 1960's technology. Last winter someone forgot to plug it in after it was used the automatic water drain did not work. The locomotive is not being scrapped out because of it.

 

[CenTex Farmall]

We've had tankless for over 15 years now. First a Bosch and then a Takagi. The Takagi is outside. It is designed to be outside and uses a power draft system. It has the automatic freeze prevention. The unit will fire up for a short interval when is gets too cold and protect itself. If there are exposed lines going in and out then they may not be protected. Sounds like the propane supplier has some weird hang ups. Water heater is no different than any other gas appliance. They have a lot of built in safety features.

The Takagi has has had zero problems and has a control inside for adjusting the water temperature.

Our water will eat a water heater tank in less than five years. Any plumbing has to be copper or red brass to live.

 

[Hobo,NC]

I never had and issue with mine mounted outside...

 

[504]

The problem was two things,the furnace is in the attic,and after I figured out what the problem was I made the heating and air company add a fresh air vent to the furnace. In the summer I would shut off the fresh air vent,one winter I forgot to go up and open it again. When this electric one goes bad I will go back to gas. Room is why I went with a tankless,I couldn't see a reason to put a heater 50 feet from the bathroom or make a bedroom smaller to make room for a tank. The gas heats faster and the 150 amp water heater takes up a lot of space in the fuse box.

 

[buickanddeere]

A tank heater is preferred if you have kids or wives that take long showers . Eventually the water will go cold and they will get out .
With a tankless heater the water stays hot . They only leave the shower when hungry or to take a phone call .

 

[showcrop]

(quoted from post at 13:53:36 01/01/21) The problem was two things,the furnace is in the attic,and after I figured out what the problem was I made the heating and air company add a fresh air vent to the furnace. In the summer I would shut off the fresh air vent,one winter I forgot to go up and open it again. When this electric one goes bad I will go back to gas. Room is why I went with a tankless,I couldn't see a reason to put a heater 50 feet from the bathroom or make a bedroom smaller to make room for a tank. The gas heats faster and the 150 amp water heater takes up a lot of space in the fuse box.

504, your attic needs to have way more venting than you apparently have. You need to have continuous vent under your soffits as well as continuous ridge vent. If you alrrady have those you should add gable end vents.

 

[504]

Think about it,a furnace like an air conditioner is a sealed unit. Air goes in and air goes out,it
just moves enough air the furnace pulls a vacuum on the living part of the house. (Well it did 18
years ago) The ridge vent is 80 ft long,eves would be 160 ft. THe furnace should have had a fresh
air make up vent.It s fixed now.

 

[GordoSD]

How does your propane supplier know what is in your house, and why?

 

[Two Dogs]

Yes, inquiring minds want to know. TDF