Disinfecting with on-demand water heater

[dsherman26]

Always disinfected the water system in our old popup (per Forest River instructions) using 1/4 cup bleach for 10 gallons of water, but that didn't have a water heater. All the procedures I'm seeing say "bypass water heater" and run the bleach solution through the water lines. The Forest River manuals for our current one haven't caught up to the fact there's an on-demand water heater and no bypass valves. The on-demand has very little capacity, just want to make sure running the bleach solution through it won't cause any problems.

[Cruzrtwdgt]

Originally Posted by dsherman26

Always disinfected the water system in our old popup (per Forest River instructions) using 1/4 cup bleach for 10 gallons of water, but that didn't have a water heater. All the procedures I'm seeing say "bypass water heater" and run the bleach solution through the water lines. The Forest River manuals for our current one haven't caught up to the fact there's an on-demand water heater and no bypass valves. The on-demand has very little capacity, just want to make sure running the bleach solution through it won't cause any problems.

My XLR has a Furrion on demand water heater and it has bypass valves. Just install them, its very easy.

[jimmarako]

Its OK to run the bleach solution through the water heater. Just drain it then flush system with fresh water. Your not suppose to tun anti freeze through the water heater.

Jim M.

[NMWildcat]

I run the bleach solution through my Girard on-demand every time I disinfect. I let it sit there over night before I flush it out. My RV is almost 12 years old and it hasn't caused any problems I have noticed.

[dsherman26]

Originally Posted by jimmarako

Its OK to run the bleach solution through the water heater. Just drain it then flush system with fresh water. Your not suppose to tun anti freeze through the water heater.

Jim M.

The manual for my Furrion says it's OK to run antifreeze through it.


Thanks all, guess disinfecting is not going to be much different from the popup.

[Chuck_S]

The reason to not run anti-freeze thru the water heater is it simply wastes six (6) or more gallons of antifreeze. Once the water heater is drained any residual water in there can freeze safely since there's plenty of expansion room.

There's no reason to use anti-freeze at all. Empty plumbing can't freeze by definition. Just drain and blow out the plumbing. No one I know uses antifreeze when they winterize their summer cottages -- they simply drain the systems.

Tasteless antifreeze does not exist.

-- Chuck

[5picker]

Originally Posted by Chuck_S

The reason to not run anti-freeze thru the water heater is it simply wastes six (6) or more gallons of antifreeze. Once the water heater is drained any residual water in there can freeze safely since there's plenty of expansion room.

There's no reason to use anti-freeze at all. Empty plumbing can't freeze by definition. Just drain and blow out the plumbing. No one I know uses antifreeze when they winterize their summer cottages -- they simply drain the systems.

Tasteless antifreeze does not exist.

-- Chuck

I believe this thread is about tankless, on-demand water heaters.

And all the summer cottages in our part of the world I'm aware of use antifreeze just like we do in our R/Vs. It's not the same everywhere.

[dsherman26]

Originally Posted by Chuck_S

The reason to not run anti-freeze thru the water heater is it simply wastes six (6) or more gallons of antifreeze. Once the water heater is drained any residual water in there can freeze safely since there's plenty of expansion room.

There's no reason to use anti-freeze at all. Empty plumbing can't freeze by definition. Just drain and blow out the plumbing. No one I know uses antifreeze when they winterize their summer cottages -- they simply drain the systems.

Tasteless antifreeze does not exist.

-- Chuck

Thanks, but the question was about disinfecting a tankless on-demand water heater, which doesn't hold 6 gallons. About a pint, actually. Some folks have found their expensive tankless on-demand water heaters can still hold a small quantity of water even after draining the lines and blowing them out with air, and they crack when they freeze. Perhaps that's why Furrion approves winterizing their expensive tankless on-demand water heaters with antifreeze so it doesn't get freeze damage. Yeah, I think I'll keep using the pink stuff, as I have for the last 19 years of owning an RV. I don't really know what the pink stuff tastes like though, since I flush out the pink stuff and disinfect the water system every spring.

[Chuck_S]

Don't be pedantic. Use of antifreeze in ANY water heater isn't necessary once drained.

-- Chuck

[NMWildcat]

Originally Posted by Chuck_S

Don't be pedantic. Use of antifreeze in ANY water heater isn't necessary once drained.

-- Chuck

Now Chuck, your inexactitude is showing! (Does the smiley face help?)
On-demand and tank water heaters have different maintenance and operations. Tank water heaters don't require antifreeze, as after draining, there is ample space for any left over water to expand w/o any damage being done. On-demand has no space, so any water remaining can cause a pipe to burst.
That being said, antifreeze may not be necessary for a properly blown out and drained on-demand, but it sure doesn't hurt. Same as the rest of the RV water system.

[wolfnwillow]

As usual but not as bad as many, the thread got hijacked, somewhat. A topic for another time. I am with the OP and have the same question and can't find the answer, yet. As it wasn't answered here.
Researching the subject and talking to Lippert, on-demand have copper pipes and should not have chemicals, i.e. bleach put in them. They also do not have by-pass valves as they should have RV antifreeze added when winterizing.
So how do we sanitize the whole system, including the on-demand? When reading about vinegar, it has to be one to one and heated to be effective. That's a lot of vinegar even if you only add half a fresh tank. 6-7 gallons of vinegar?!
So back to the original question. How do we sanitize the system without bleach?

[NMWildcat]

Originally Posted by wolfnwillow

As usual but not as bad as many, the thread got hijacked, somewhat. A topic for another time. I am with the OP and have the same question and can't find the answer, yet. As it wasn't answered here.

Researching the subject and talking to Lippert, on-demand have copper pipes and should not have chemicals, i.e. bleach put in them. They also do not have by-pass valves as they should have RV antifreeze added when winterizing.

So how do we sanitize the whole system, including the on-demand? When reading about vinegar, it has to be one to one and heated to be effective. That's a lot of vinegar even if you only add half a fresh tank. 6-7 gallons of vinegar?!

So back to the original question. How do we sanitize the system without bleach?

See my post #4. The bleach solution is so mild (diluted), that I don't see how it can harm anything. Chlorinated city water has been used in houses with copper pipes for ages.

[5picker]

Originally Posted by NMWildcat

See my post #4. The bleach solution is so mild (diluted), that I don't see how it can harm anything. Chlorinated city water has been used in houses with copper pipes for ages.

X2
The ratio of bleach for sanitation won't hurt your water heater.

[dsherman26]

Originally Posted by wolfnwillow

As usual but not as bad as many, the thread got hijacked, somewhat. A topic for another time. I am with the OP and have the same question and can't find the answer, yet. As it wasn't answered here.
Researching the subject and talking to Lippert, on-demand have copper pipes and should not have chemicals, i.e. bleach put in them. They also do not have by-pass valves as they should have RV antifreeze added when winterizing.
So how do we sanitize the whole system, including the on-demand? When reading about vinegar, it has to be one to one and heated to be effective. That's a lot of vinegar even if you only add half a fresh tank. 6-7 gallons of vinegar?!
So back to the original question. How do we sanitize the system without bleach?

Hi, OP here, I just disinfected with the bleach solution. I also ran the pink stuff through it in fall, and had no issues come spring.