For questions generally relating to the hot-water supply system of a typical residential or commercial building, primarily regarding the heating mechanism itself (a traditional hot water heater tank, tankless heaters including "point-of-use", boilers and heat exchangers, etc).

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5
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3answers
2k views

Why does hot water come from the faucet when only the cold water tap is on?

On occasion, when I open the cold water tap on the kitchen sink, the flow from the faucet briefly becomes warm: it starts cool, becomes warm for about 30 seconds, and then returns to the desired cold ...
0
votes
1answer
58 views

Hot water running out, already replaced both heating elements and both thermostats

Our hot water runs out during one not-too-long shower. By the end of the shower, I have the cold water completely off and the hot water coming out is only lukewarm. My husband already replaced both ...
1
vote
1answer
68 views

How does decalcifying work, and is it something I need?

We recently had to replace our water heater because of lack of hot water, age (12 years to the day almost) and sediment build up (it was higher than the lower element; we purchased the home 7 months ...
0
votes
1answer
93 views

How close can an electric water heater and an electric furnace be to each other?

How close can an electric water heater and an electric furnace be to each other? My water heater is 7 inches from my furnace. I need 4 inches so that I can install a water softener and wash sink. So ...
2
votes
3answers
186 views

Does a thermocouple need to be screwed in to work?

I'm recently having trouble with a water heater. The pilot light with ignite just fine, but will go out after releasing the reset button, even after holding it for over a minute. That makes me think ...
7
votes
4answers
14k views

Why does my kitchen faucet have low pressure after the water heater was replaced?

I recently replaced my water heater, and since then, the water pressure for my kitchen faucet is really, really, low. None of my other faucets seem to be affected (bathroom, shower, etc.). I can't ...
5
votes
2answers
926 views

Why does pressure relief valve state 'Not for Use with Water Heaters'?

So I replaced my 6.5 year old electric hot water (installed with house built in 06') heater and used an identical plumbing setup as my previous install. My previous (and now current) install has a ...
1
vote
3answers
162 views

Combi boiler doesn't realise it's already lit

I have an Ariston Eurocombi (A23). The problem is it doesn't realise the flame is lit. When I start it up and cause demand (run hot tap or turn on heating) it fires up the flame correctly, however, ...
3
votes
5answers
268 views

Is it okay to flush water heater onto the drip pan with drain hole?

Our water heater is on the second floor and we need to have it flushed. It has a drip pan with a hole that has a tube attached to it. Common sense tells me that I can flush the water heater directly ...
6
votes
4answers
3k views

Why is the first shower of the day is colder than the second?

Description Since I've moved into this house, I've noticed that the first shower of the day is colder than the any subsequent shower. More specifically, if no hot water has been used for a while, ...
0
votes
1answer
259 views

Desuperheater vs Heat Pump Water Heater

I'm having a geothermal heating system installed in my home, and the contractor recommended heating my water using a buffer tank and desuperheater, which is a device that cools the refrigerant lines ...
6
votes
4answers
8k views

Should the water heater be shut down if the water main has to be turned off?

I have a brand new AO Smith 50gal Gas water heater, today there was a pipe burst from the cold spell we're having in the states currently so I had to turn off the water to the house until the plumbers ...
0
votes
2answers
110 views

How much distance do I need to branch from water heater?

I moved my washer and dryer next to my electric water heater. I would like to know how close to the tank can I branch the hot and cold water lines. I would like to use a 3/4 to 1/2 inch reducer at the ...
0
votes
1answer
128 views

Why is the pilot on my GE water heater turning off when the burner turns off?

I have 2 GE 28 gallon water heaters, both of which have the same problem. The water heater is turning off after a while, and I have to light the pilot again to got hot water. What could be causing the ...
4
votes
2answers
804 views

How do I prevent harmonic resonance hum in PVC vent of newly installed hot water heater?

I just had a new power vented water heater installed (HTProducts Phoenix Light Duty) in our crawlspace. The contractor that put it in used part of the existing 3" concentric vent from the furnace we ...
3
votes
1answer
244 views

Why does my Rinnai Infinity water heater fire up after turning off the cold tap?

I have a Rinnai Infinity XR20. It's about 3 years old. I've just recently noticed a peculiar issue with it that I hadn't noticed before. If I turn on a cold tap like the one to the garden hose and ...
1
vote
1answer
39 views

possible cause for the water heater being unable to be lighted

The water heater could not be lighted. I tried several times without being successful. What could be the possible causes for the water heater to fail to be lighted. This water heater is only 1 and ...
2
votes
2answers
202 views

How to calculate potential energy savings from using a tempering tank?

I have a boiler (oil) with integrated water heater (3.5 gallon). I don't have problems with running out of hot water but I do wonder if having a tempering tank before the boiler would save money on ...
1
vote
1answer
283 views

How can I prevent a tankless propane on-demand water heater from freezing up in very cold climates?

We are considering installing a tankless propane on-demand water heater in a residential setting, where multiple tenants use a shared bathing facility (presently served satisfactorily by a 40 gal ...
2
votes
2answers
373 views

How can I prevent the intake vent for an on demand water heater from getting plugged?

We have a Navien on demand cold water heater. The intake and outlet vent pipes run out through the poured concrete foundation and have a plastic grill on the end. If the intake vent is blocked in any ...
0
votes
0answers
1k views

Why won't the burner on my gas water heater light?

I have a Whirlpool 40 gal gas water heater that I got around 2 years ago. Doing dishes tonight, I noticed the warm water was getting colder. When I went to check the water heater, the signal light ...
0
votes
0answers
27 views

Why is the water heating up when it's switched off?

Our central heating is timed to come on twice a day and water heating is off. However, water is heating up. British Gas engineer unable to come up with solution (has changed a valve on hot water ...
1
vote
0answers
80 views

Can a water heater be installed overhead?

Sorry for the long preamble: I'm doing a remodel which involves building a new attached garage. At the same time, I'm replacing the water heater because it is ancient. I have considered a ...
5
votes
3answers
6k views

Is it time to replace my 20 year old water heater?

My water heater (gas) shows a date of 1991 on it, although the house was built in 1993. There is nothing wrong with it. It is a little slow to heat the water up, sometimes taking almost 5 minutes to ...
0
votes
1answer
247 views

Is this electric water heater wiring correct?

I recently re-wired my water heater from 120v to 240v. I'm not sure why it was wired with 120v to begin with, but it was not providing enough volume of hot water. I looked up basic thermostat wiring ...
2
votes
1answer
51 views

Does a broken TPR valve disable the water heater?

Would the pressure release valve going bad on a water heater cause the water heater to quit working?
2
votes
1answer
3k views

Why is my electric hot water heater producing lukewarm/cold water?

Yesterday after returning home from work I discovered my hot water is not working. When you turn on the faucet (any in the house) just a little warm water comes out and then it turns cold. I checked ...
0
votes
2answers
3k views

What could cause a shower to give warm water for a few seconds, then only cold water?

The house has four bedrooms. The 40 gallon gas water heater is about 60 feet from this shower. The house is a one story house in flat terrain. I have already changed the mixing faucet for the shower, ...
0
votes
3answers
313 views

Is it safe to install this hot water tank from ebay?

Is it safe for me to replace my electric hot water tank with this continuous electric unit that I bought on ebay? (I'm in Australia) Technical Specifications rated power 6.0KW ...
3
votes
1answer
763 views

Why does my gas water heater's pilot light go out when I replace the outer door?

I have a 9 year old Bradford White gas water heater, model MI403S6FBN4. The pilot light went out today, and when I went to re-light it, it stays lit while the pilot button is held down, and it stays ...
1
vote
1answer
84 views

Why is my electric water heater not working?

I have electric heating in my flat. My water is not heating up even though the timer light comes on and the immersion light comes on. Any idea what it could be?
0
votes
1answer
108 views

How do I turn off my water heater drain?

I read that draining the water heater is general good practice. The problem is that I don't know how to turn off the draining plug. It kept draining water through the night. Here is a picture of the ...
0
votes
1answer
37 views

Inline water heater temperature floor?

I have an inline water heater. Once it gets hot it will stay that way for 20+ minutes at a time easily. When the shower gets used it feels like their is a floor in how cold the water will get - if ...
5
votes
3answers
2k views

Is it OK to drill through a jack stud/full stud pair to cut a hole for water heater drain pipe?

I just had a new water heater installed in my garage. My city building / plumbing codes require that the water heater overflow drain be drained to the outside of the house. Situation: The heater ...
6
votes
2answers
4k views

What can I do about high water pressure that is causing a leak?

One of our showers has an intermittent leak, and I've figured out that it happens when the hot water heater is on. There's no expansion tank on the cold supply side for our hot water tank, so I'm ...
0
votes
1answer
2k views

How should I connect nipples to a hot water heater?

I recently installed my new hot water heater. I know nothing about plumbing and my installation procedure was informed only by sketchy home depot employees and youtube. One of the issues I'm having ...
5
votes
1answer
142 views

Flush a gas powered water heater, not sure if it's ever been done in 15 years. Will it survive a flush?

I'm concerned that there might be seals that are bad, or corrosion keeping things waterproof. It looks great on the outside, But I don't know how efficiently it is working - I've never owned a home ...
2
votes
3answers
3k views

How does a water-heater know when to turn on?

Now that it is getting colder, we have noticed that when we get home from work, our water is not that hot. It was warm at best after a four-day trip. The water heater is in an unheated basement, ...
2
votes
1answer
197 views

Plumber told me it's unsafe to drain my water heater — what should I do?

We are new homeowners. Our 11-year-old 2nd-floor water heater was leaking and the first plumber who came told us he would need to come back with a partner to take it away. I asked if I could drain ...
0
votes
0answers
163 views

Can I reuse an abandoned roof vent?

I have a house that has an old 8-10 inch diameter vent that used to be used as stove/oven vent. I think that newer gas ovens don't require venting like a water heater needs (ie they don't have a ...
11
votes
4answers
776 views

Which water heater types do you recommend?

I would like to upgrade my current water heater with one that Is able to produce/store more heated water so I won't run out Energy efficient Inexpensive What are the advantages/disadvantages to ...
2
votes
2answers
561 views

Properly venting a gas water heater

Ahh, the joys of an old house. The former owners of my house did some funky stuff with venting the water heater. Let me explain: the water heater is in the basement there is a 3 in single walled ...
1
vote
1answer
713 views

How do I diagnose and fix an electric water heater leak?

I have an Electric Water Heater, seemingly leaking from the top of the tank. The "wells" on top are filling up with water. There are no noticeable leaks from the pipes above. Each water attachment ...
3
votes
1answer
765 views

How can I prevent water from entering through water heater/furnace exhaust vent?

I have an exhaust vent in my basement (Amerivent Type B) which takes the exhaust from my gas furnace and water heater goes out the basement wall, and up my chimney. A little bit water is coming in to ...
2
votes
1answer
574 views

Why does my Paloma tankless water heater turn off randomly without errors?

We have a Paloma Tankless water heater, model: PTG-74PVN that shuts down when in use for a few minutes. There is no code displayed on the screen, it just powers down. This started happening a few ...
0
votes
1answer
328 views

how do I remove a stubborn element from a water heater?

I need to pull and replace the elements in my water heater. the problem is, I can't get the old ones out. my channellocks can get a grip, but slips off pretty easily. is there something better for ...
4
votes
3answers
922 views

What failure modes are there for electric water heater elements?

What would be the cause of the elements to go out in my electric water heater? My wife is convinced that it's because the water heater hasn't been drained/flushed in the past 3 years. I was also ...
1
vote
1answer
140 views

What are the three copper connections to my water heater?

Why do I have 3 copper pipes in my gas water heater? It seems two are cold and one is hot. All videos I see online show only two pipes; one for cold coming in, one for hot going out.
0
votes
1answer
919 views

How can I remove a temperature and pressure relief valve that seems to be stuck?

I have a hot water heater relief valve that is leaking heavily. The water heater manual states I should replace the valve (which is OK by me). Unfortunately, I am not able to remove the valve as it ...
17
votes
1answer
9k views

What temperature should I set my hot water heater to?

When adjusting my hot water heater, what temperature should I set it to? Is the answer different if you have: Concerns about diseases A dishwasher Young children or elderly that can be easily burned ...