29 votes

Why does our hot water tank start working when we shut off the cold water valve to the tank?

I suspect the pipe that puts water into the tank, known as the dip tube, is broken inside. So when you use hot water, the cold water enters at the top, when it should enter at the bottom. This would ...
Tiger Guy's user avatar
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28 votes
Accepted

How do electric hot water heaters explode and what can be done to prevent that from happening?

Yes, that's a scary article but keep in mind that both safety devices have to fail to have the tank explode. The pressure release valve and the high limit on the thermostat both have to malfunction. ...
JACK's user avatar
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28 votes
Accepted

Turn off hot water without hot water valve

My approach would be to turn off the water heater and the cold supply. Then open a hot tap below, or as close to the area of the leak, to drain the hot pipe. Then be prepared to catch the remaining ...
Solar Mike's user avatar
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24 votes

How do electric hot water heaters explode and what can be done to prevent that from happening?

Consider the sources; it is plumbers giving you a scare story to get you to hire them. See also "aluminum wiring". It will take a chain of 3 events at once: failure of the thermostat, causing ...
Harper - Reinstate Monica's user avatar
15 votes

How to maximize hot water production given my electrical panel limits on available amperage?

Given the details from all the chatter in your comments, I see four practical solutions: Install a conventional 55 gallon electric or heat pump 80 gallon tank with an added tempering valve. Set the ...
KMJ's user avatar
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14 votes

Why does our hot water tank start working when we shut off the cold water valve to the tank?

Like Tiger Guy said, the dip tube might be broken, but and here's the big BUT.... The hot and cold connections might be reversed. Normally this results in trapped air near the top of the tank, ...
George Anderson's user avatar
13 votes

Is it safe to shut off an electric water heater for long periods of time?

All hot water heaters already have a regulator. Otherwise the water would boil over and you'd have a boiler explosion. You can feel free to shut off an electric water heater for an extended period of ...
Harper - Reinstate Monica's user avatar
11 votes
Accepted

Why does my water heater's drain line rejoin the outlet pipe?

What you describe sounds like a Gravity Fed Hot water re-circulation system. It's designed to keep hot water available at the kitchen sink without having to flush cold water out of the pipe first. ...
Tyson's user avatar
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10 votes
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Are electrical screws a standard diameter?

There's no reason it would not be a locally standard size (given a British location based on the label, presumably metric or pre-metric British Standard threading) so some basic measurements (no ...
Ecnerwal's user avatar
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9 votes

How do I get 150F water to the dishwasher?

You don't. Let the dishwasher do it for you. I have read in a maintenance manual that the ideal temperature for incoming water to a dishwasher is 150F. Was it a maintenance manual for your actual ...
manassehkatz-Moving 2 Codidact's user avatar
9 votes

Hot water tank loses heat by closed loop gravitational circulation - need to improve thermosiphon

OK, so you have a 3-loop system. The inner loop is freon, for the heat pump. The intermediate loop is service water (or antifreeze) which you heat/store in a 300l (80 gal) tank. Then you use the ...
Harper - Reinstate Monica's user avatar
8 votes

How do electric hot water heaters explode and what can be done to prevent that from happening?

An electric water heater explodes when the water in it starts boiling, producing pressurized steam that causes the heater to rupture. In order for this to happen, three things all need to fail; if ...
Mark's user avatar
  • 591
8 votes

How to maximize hot water production given my electrical panel limits on available amperage?

Identifying your service size The electrical panel says 125 amps but the wire gauge coming in appears to be a 4 gauge Most service panels of this size have internal busing rated for 125A. That's ...
Harper - Reinstate Monica's user avatar
8 votes
Accepted

Adding an additional stop valve to existing supply stop valve

Add-on Stop Valve: The downstream add-on stop valve you are looking for is called an inline "repair stop valve". Its upstream end has a captured nut and seat to exactly fit on the "...
Armand's user avatar
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8 votes
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Replacing leaking valve where the only upstream source is at the hot water tank itself

You aren't going to hurt the water heater by turning off the hot water outlet, that's what it's for. That pipe in the middle is your pressure relief if anything did happen. As far as water draining ...
JD74's user avatar
  • 1,824
7 votes
Accepted

Is wrapping Roxul around hot water tank pipe a fire hazard?

No. As you seem to be aware, Roxul is a mineral wool product, and mineral wool is fireproof. You're right that it will "trap the heat" but this is exactly what you want and the result will be less ...
iLikeDirt's user avatar
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7 votes
Accepted

PEX pipe burst: what else needs to be fixed to prevent it happening again?

PEX pipe does not corrode or otherwise interact with copper or other materials the way dissimilar metals do. It's essentially an inert substance under normal circumstances. The bulges and darkened ...
jwh20's user avatar
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7 votes
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Replacing toilet shut-off valve and need to turn off water; Need to turn gas water heater to pilot?

Do I need to set the water heater to pilot, in order to avoid the dangerous scenario outlined above? Doing anything to our water heater makes me a bit nervous. NO, In the amount of time that it will ...
Alaska Man's user avatar
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7 votes
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Why does the water from my shower get hotter when I use a shut-off valve?

Let's flesh this into an answer. This happens with my kitchen faucet and one of those "quick-flip - not quite total shutoff" valves that screw into the aerator. My guess is that some hot ...
Ecnerwal's user avatar
  • 214k
7 votes

Can a water heater that's been stored for several years be put back into service?

If the water supplied to your house is potable, there really isn't much in there to grow. That's the point of water supply treatment, followed by water distribution at sufficient pressure that leaks ...
Ecnerwal's user avatar
  • 214k
6 votes

How do electric hot water heaters explode and what can be done to prevent that from happening?

Well, the answer is right there in the article you linked: Always check your hot water heater’s pressure relief valve to ensure it is in good working condition. If you have any concerns that ...
PhilippNagel's user avatar
  • 4,957
6 votes

Why is this apartment water heater so much more expensive than my bigger home one?

I think it's fear of downgrading. I think the pro plumbers are unwilling to downgrade them. For instance, the latest Codes require water heaters to have better insulation than they did before. This ...
Harper - Reinstate Monica's user avatar
6 votes

Unable to turn knob on Rheem hot water heater to pilot

Below is a picture of the lighting instructions for your water heater taken from Rheem's website. Make sure to follow the lighting instructions carefully and do not skip any steps. This same ...
MonkeyZeus's user avatar
  • 16.6k
6 votes

Can I switch the hot and cold water supply to improve the pressure of hot?

Your question boils down to "please validate my wonky idea" and I will absolutely NOT. Yes, you can do it but you shouldn't. At best your proposal is something that would be done in a super ...
MonkeyZeus's user avatar
  • 16.6k
6 votes

Hot water tank loses heat by closed loop gravitational circulation - need to improve thermosiphon

As mentioned by others, the tubes should be insulated to reduce the thermoflow and losses in general. If the thermosiphon is not directly installed close to the tank's in- and outlet, the uninsulated ...
xeeka's user avatar
  • 2,548
6 votes

Can I wire a switch to toggle between the top and bottom outlets of a 1 gang receptacle

Crazy but in a good way. Brilliant actually. Use any common 3-way switch, I don't see a problem with it. The only issue that might call for a 2-gang switch box is the need for GFCI protection on both ...
Harper - Reinstate Monica's user avatar
6 votes

How can I decrease water flow to tub spout?

The issue is due to a tankless (or on-demand) hot water heater having no reservoir of hot water to keep up with high demand. The water is heated immediately with 14 kW of electricity. Below a specific ...
DrMoishe Pippik's user avatar
6 votes

Do I need to turn off gas water heater if draining pipes?

If you are draining your pipes to avoid freezing, then you will also want to drain the water heater as it will freeze and burst also, given enough time in freezing temps. 36-48 hours is certainly ...
jwh20's user avatar
  • 23.3k
6 votes

Is it a good idea to place an electric boiler on the warm water line?

Point of use water heaters are a common solution to the problem you are trying to solve. Most operate on 120 Volt and can plug into a standard outlet and take about 12 amps. You can set the ...
JACK's user avatar
  • 80.5k
6 votes

Is it a good idea to place an electric boiler on the warm water line?

First, I would actually measure your numbers. Because I find 15l of water in the pipe to be non-believable. That's 100m (300'+) if the pipe is 3/8" trade size, 60m (200') if 1/2" pipe, and ...
Harper - Reinstate Monica's user avatar

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