Review" Under-Sink Mini-Tank Water Heater

TromboneAl

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Jun 30, 2006
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After about 10 days with the new water heater, I can tell you that it works very well, and was worth the installation headaches.

We simply have hot water all the time. It takes about two seconds for the hot to start coming out of the faucet. Lena loves it, and says it was the "best thing we've done for a while."

No waiting to wash your hands, fill up a pot, or start the dishwasher.

My kill-a-watt tells me that it used 2.79 KWH in 49 hours, which means an average wattage of 56.9. At our rate that means it will cost about $75/year to operate. I set the temp to about 120 degrees, so that it won't be too hot for hand-washing. If we didn't have a two-lever faucet, I might set it higher.

If I turn the whole-house water heater off, hot water lasts for about 70 seconds, followed by a gradual cooldown (faucet runs at about 1.5 gals/min). Normally, by that time, the hot water from the whole-house water heater has reached the faucet, so it never cools off.

One should service it (descale) every two years -- I think I'll have the plumber do it.

In summary: Two thumbs up.
 
Thanks, I was gonna ask for an update.

I was thinking you might still get a lag between the little tank, and the main hot water, so that the water might run hot-warm-cool-hot. Good to hear it works well at 120F.

edit/add: You know, you might even save money by running the hot water for more than 70 seconds each time. If hot water is flowing from your propane tankless by then, you will only use electricity to maintain the temperature, rather than raise the temperature. And if the tankless provides well above 120F, and you draw enough to refill the tank with heated water, it won't even need to come on again until the temp has dropped.

But if you stop at 70 seconds, the tank has been filled with cool water, and will have to raise it to 120F.

-ERD50
 
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I am so envious! My daughter had that in a rental house, and the water was hot enough to even make instant coffee or tea.
 
The tankless is also set to 120, since the installer chose a cheaper controller. I might get a new controller and increase it some day.

I'd increase the mini-tank temp above 120, but since we have a two handled faucet, it's simpler to have the hot water at a good temp for washing your hands. We chose a two-handled faucet since a one-handled one often would cause the tankless to start even when you only wanted cold water.

I realized that if the mini-tank water heater isn't on, it will take a lot longer to get hot water from the faucet, but that will only happen during power outages (tankless can run without power).
 
I realized that if the mini-tank water heater isn't on, it will take a lot longer to get hot water from the faucet, but that will only happen during power outages (tankless can run without power).

My propane fired tankless water heater requires 110v power for the control panel, fan, and the pilotless electronic ignition. Yours must be different.
 
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My propane fired tankless water heater requires 110v power for the control panel, fan, and the pilotless electronic ignition. Yours must be different.

+1 mine requires power too. Never heard of one not requiring power. What do you have Al?
 
Al's tankless heater is electric, not gas. I think he meant that without power water can just flow through the heater unimpeded.
 
The tankless uses propane, but requires a little electricity to run an exhaust fan and the control stuff. When the power is out, I feed it 110 from an inverter connected to the car.

Sent from my Nexus 7 using Early Retirement Forum mobile app
 
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