Lukewarm Water

Hi All,

So two weeks ago, we experienced a leak from the dishwasher - it was apparently a hose issue, a plumber came and dealt with it, no problem. Since that time, however, we've only had lukewarm water. We called the plumber, he said that the two things couldn't be related. I went down to the hot water heater, tried boosting the temperature to 130. Briefly, the water was warmer, then was lukewarm again.

We called the plumber back, he changed the thermostats on the hot water heater, but said the elements were ok. For about an hour, the water was the right temp, but then as soon as he left, it went back to the previous lukewarm temperature.

Any ideas as to what the issue might be?

Thanks!
RJM

For one, if you are on an electric hot water tank your temperature should never be below 130F. You are at risk of legionella bacteria growth. If you find that too much, you must install a mixing valve.

Second, without seeing it it sounds like a bad upper element. I'm not sure what tests he did though. Elements are cheap, replace them both.

Matt30 said:

For one, if you are on an electric hot water tank your temperature should never be below 130F. You are at risk of legionella bacteria growth. If you find that too much, you must install a mixing valve.

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The thermostat(s) should never be set above 120 as scalding can occur in children and the elderly (You can cheat somewhat by raising the lower thermostat to 130 but requires being careful of which side of dead-banding the WH is on when using < This IMO only).

Also, killing bacteria usually requires a minimum temp of 140 in the tank.

Well, not sure what google page you're looking at today but my CODE BOOK and health department tell me an electric tank be set at a temperature no less than 130F. Scalding is exactly the reason why mixing controls are code on new builds. You don't wanna get your kids sick, set it right. You don't wanna scald them, put in a mixing valve.

I keep forgetting this is a Canadian site.

Maybe your rules differ in some areas?

Actually, to control legionella bacterium, the temp should be @ 142 - 143 degrees and hotter if you can afford the utility bill.

And I am pretty sure WH manufacturers INSTALL INSTRUCTIONS say 120 degrees unless a TMV is incorporated.

Do you think that code book is able to keep up with advancing technology?

KULTULZ said:

Do you think that code book is able to keep up with advancing technology?

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Of course. If it's gonna be released to industry, it has to comply. Hence why I receive yearly code updates, and a complete new code book is released every 5 years.

Just exactly what does your code book say about raising the WH set temp over 120 degrees? Does it call for a TMV?