Tankless water heater maintaince
 

So I got my tankless water heater today.
And figured I will break from tradition and read the manual before I install it.
It looks like in the manual they highly recommend adding provisions to hook up an external pump so that vinegar or citric acid solution can be circulated through the heat exchanger to remove scale build up.
The manual makes this maintaince sound pretty important.

This isn't a problem for me I have extra brand new 3/4 inch valves I bought from the scrap yard for maybe $1 each and I have a pump that can circulate the recommend volume (2 to 4 gpm).

The tankless heaters are not as maintaince free as I thought.

If you want low to no maintenance get an electric tank heater and put a magnesium anode in it.

Annual maintenance depending on how hard your water is.
http://www.noritz.com/blog/biggest-m...-water-heater/

I was lucky and got a free isolation valve set. Here is a good price on a set with free shipping
https://www.build.com/takagi-9007605...g!188197043119!

On either side of the heat exchanger, I put on a set of "t" fittings that stub out to gate valves. In the 29 years I have used this, I have not had to run acid through it. And I have moderately hard water. The exchanger is a cupronickel type that expands and contracts with each use. This largely eliminates development of hard water scale.

But if I had not put on those fittings/values, then it would have plugged up with scale quickly . . . ! Ha - the perversity of life . . ..

The pump can simply be an inexpensive "Little Giant" type, and then a couple lengths of old garden hose and a plastic bucket for the vinegar.

No biggie.

I really like the tankless system.


Steve

I was just going to cobble together my own valve isolation. I have about a dozen 3/4 and 1/2 inch valves in my plumbing collection.

They both work the same way. If I did not get mine for free I might have made my own isolation valves. I was just pointing out what I used.

I am also considering a hot water circulating pump if the flow will kick on the burner.

I don’t know what unit you ended up with. Most units will turn on at different flow rates.
Mine kicks on at a fairly low flow rate. I use a circulating pump that gets turned on with the light switch in the bathrooms and the kitchen sink. I run it different amounts of time depending how far away from the unit.
What unit did you buy?

Oops I never did give make and model number.
It's a "Marey" model GA16NGETL
This is a smaller unit, at 4.3gpm water heating capacity this one is not really intended to be a whole home unit.
It can use the existing gas system and with 3 inch intake and exhaust requirement it will work fine with the existing 3 inch exhaust and 4 inch abandoned wall heater exhaust vent in my house.

Whole home units ate typically 7.5gpm. And they need large 5 inch intake and exhaust ducts. Existing exhaust vents are likely 3 or 4 inch Then the existing 1/2 inch 0.4psi gas line systems in most homes may not be able to provide enough gas.

Your unit.
Activation Flow Rate: 0.66 GPM
Applicable Water Pressure: 1.45 PSI - 138 PSI (0.1 - 9.5 bar)
With these specs it should kick on with a circulating pump

Thanks, I was looking for that in the manual but wasn't finding it.

I finely got it going and I like it.
The only thing don't like is it not kicking on at real low flow.
I may consider putting a tiny electric tank water heater under the sink or a small tankless that handles low flow really well.

Mine has an Activation Flow Rate: 0.40 GPM. When I was searching for a unit I looked for a low Activation Flow Rate.

You can make your sinks flow a higher rate.

Pinball,

Remind us of the specific tankless water heater you have. Really 0.04 GPM? That is a trickle!


Steve

Steve that was a typo it is about 1/2 gallon that is about as low as I was looking for. .40 GPM
(sorry that would be crazy low.)

T-H3-DV-N - 199,000 BTU Natural Gas Indoor Condensing Ultra-Low NOx

Spec sheets.
http://www.takagi.com/media/19483/24...TRGSS01512.pdf

ULTRA-LOW NOX 0.95 ENERGY FACTOR
Power Direct Vent Design
• Exhaust, 3” PVC Venting up to 70 feet or
4” PVC Venting up to 100 feet

I have been very happy with it. The intelligent circulating pump really helps. In my bathroom by the time you use the water warm to hot water is there.

The kitchen and bathroom sinks kick it on no problem. I think kitchen sinks flow like 1.5gpm and a bathroom sink does around 1gpm.

I looking for info about how to flush my tankless water heater and I came across this site. I know the opinion that еoo much of calcium and mineral deposits can reduce the life of the tankless water heater. Regular flushing is quite beneficial for its longevity and improve its efficiency. How do you flush your water heater? What can you recommend?

I added additional valves when I installed it for this reason.
I have a few pumps I could use to circulate water with.
For the chemical I figured I would get some nitric and phosphoric acid mixture from work.

I installed the valves on my hot water heater as well when I installed it. I've honestly never used them. We have decently hard water that is softened.

I installed them as well and have never used them.
I do plan on it I bought the vinegar a year ago.

But the hoses I had for the job I used for another project.:rolleyes: