Tankless Water Heater Advice and or Experience

[Jim Nelson]

When we bought this house in '09 it had been built with the plumbing in for a solar water heater and wiring and box for solar pv system. The husband of the couple that built it passed away before they got all the stuff finished so we finished the solar water heater and pv systems. The guy that did the solar water heater said that the ideal system would be to have a tankless heater to back up the solar. We had joined Direct Buy when we bought the house because we had a lot to do to finish it up and a couple of years later they had an introductory deal on Noritz tankless heaters so we bought one for just over $600 and had it installed. It works great for us.It does take a little while for the hot water to get to the far end of the house but no more that the 40 gal. tanked system that was here when we bought it.We put in a filter system so haven't had to flush it and no problems.

The only problem we have had was the heater would cut off intermittently and the tech came out and blew out the combustion chamber with air and it works great again.

We heat with a fireplace insert so our propane usage for water and stove top is 55 to 60 gal. per year.

 

[Xfaxman]

Update.

Thanks for all the replies and information. The crisis is over for now. Problem was the pilot would not stay lit. Measured the voltage from the thermocouple, it was very low. Removed it and wire brushed the end that the flame heats, retested and the output was now high enough to keep the pilot lit.

It has been working for over a week now, so will procrastinate on replacing the water heater.

 

[dstig1]

Interesting sidebar. I just saw a product announcement in Journal of Light Construction for an AO Smith tankless water heater with new "X3 scale prevention technology" that supposedly eliminates the hard water issue. No idea how good it is or not, but I have not seen anything like that before. It is only on one line of their tankless heaters.

 

[kenmac]

Update.

Thanks for all the replies and information. The crisis is over for now. Problem was the pilot would not stay lit. Measured the voltage from the thermocouple, it was very low. Removed it and wire brushed the end that the flame heats, retested and the output was now high enough to keep the pilot lit.

It has been working for over a week now, so will procrastinate on replacing the water heater.

so, did you test the thermocouple in circuit or out of circuit ?
read about 30 mv out of circuit and about 15 mv in circuit as your safety (magnet) will use about 15 mv

 

[Xfaxman]

Out, unscrewed, put the meter leads on it, lit the pilot and held the button down to keep the flame on. Saw the meter reading go up slowly. It was over 22 millivolts when the meter lead came off the end, so I let go of the button.

Screwed the thermocouple back in, lit the pilot and it has on been ever since.

 

[LouNY]

I have considered the inline heaters to supplement my main water heater for the kitchen and laundry room as it takes a few minutes for the hot water to get to those appliances at times.
Close to 70 ft of piping from the water heater to those units.
My main water heater is a boiler mate 60 gallon tank type, I have considered replumbing and adding a different heater for the summer months instead of using the oil boiler.
But keeping the boiler warm eliminates many issues with boilers and it is very difficult to run my setup out of hot water.
Initially it was set up for a house with 6 females and myself so lots of hot water was a major concern,
this system is going on 30 years old with minimal maintenace requirements.

 

[CobyRupert]

I’ve worked with people who ran a second hot water tube “back” from just before the remote faucet and tee’d it back into the hot water pipe where it leaves the hot water tank; on the low end of the main hot water vertical riser pipe that goes everywhere else.
The idea is the height difference creates a convection loop that keep hot water continuously circulating to just before the remote faucet so you don’t have to wait for hot water when you use faucet.

Does this work? .....I never tested the actual results for effectiveness. Anybody ever try this?