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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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 ...
6
votes
3answers
28k views

What causes a water heaters relief valve to discharge water?

I have a Gas Reliance Water Heater 1212. I found recently (in winter) there is a water dip through the relief valve into a 5 gallon bucket. Sometimes, it can fill the whole bucket. Sometimes, it has ...
5
votes
2answers
1k 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 ...
2
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0answers
85 views

Where could the air in the water system be coming from?

We live on the top two floors of a small brownstone walkup. To get the heating to work upstairs I need to bleed the baseboard heater almost every other day. All faucets in the house sputter, and the ...
2
votes
0answers
920 views

What could cause my tankless water heater to make a knocking sound?

I recently replaced my water heater with a tankless unit (Rheem). After installation I noticed that whenever I turned on the hot water; or when my central heating unit would turn on, the tankless unit ...
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0answers
649 views

What dangers are associated with changing the pilot light assembly on a gas water heater?

My A O Smith ProMax gas water heater started going out at various intervals. I would re-light it and it might stay lit for a few minutes, few hours, or even a day or so. I figured it was the ...
2
votes
2answers
3k views

Is it safe to shut off cold water entering water heater?

I have a pretty bad situation at my place. I have a leaky shower faucet which has gone from drips to a steady stream. I calculated the flow at .3 gallons per minute. My very old home has no private ...
6
votes
4answers
3k views

Should I install an inline water heater for my bathroom?

It takes 3-4 minutes of the shower running before the hot water reaches my upstairs bathroom. I'd like to not have to waste all that water and time. My initial though was to install an inline water ...
2
votes
1answer
251 views

What's with the different FHR ratings of these hot water tanks?

We're replacing our tank with a more efficient one and we can't go tankless given the cold input temperatures in Canada and the amount of output we need (for a triplex with 7 people). So I've been ...
2
votes
1answer
336 views

Why does the hot water run cold at less than 'full throttle'?

I'm as environmentally conscious as the next American (probably not very) but here's an example: I like to rinse dishes that I've just washed in a stream of hot water as this works best for drying. I ...
4
votes
2answers
720 views

Should a water heater's anode be replaced?

I hear conflicting information on replacing the anode bar on a water heater or not since the water heater will be replaced anyway. Should the anode bar be periodically replaced? Why? How often?
7
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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, ...
1
vote
1answer
52 views

How do I replace a damaged valve on a water heater?

Near the bottom of my hot water tank there is a plastic valve that looks like it is used for draining the water out of it. It has developed a hairline fracture along the length of it and small jets of ...
-1
votes
1answer
1k views

How long will it be before my hot water heater blows up without a thermal expansion tank?

the county where I live put in the "check valve" or backflow device. Not sure, but I know they said you need to get a thermal expansion tank or the pressure could blow up the water heater. I spoke ...
2
votes
1answer
95 views

How do I start a cold gas heater?

The gas heater pilot light has been out for a couple of days, and I believe there is a safety mechanism that detects this, and shuts off the gas. Now, when I move the slider to the pilot light ...
2
votes
1answer
216 views

Why does my water heater stop after a few minutes?

I have a Junkers (European water heater) that works for a few minutes and then stops. Anyone have experience with this/know how I can troubleshoot? Or, would a regular plumber be able to fix it?
0
votes
2answers
677 views

What could be causing water to drip from the relief valve of my new gas water heater, again?

I installed a brand new water heater about 4 months ago, noticed that that relief valve was dripping like crazy. Checked the expansion tank and it was filled with water. I replaced it with a brand ...
7
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 ...
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0answers
122 views

Without having a pressure regulator or gauge, how would we determine what psi to set our new expansion tank to?

Without having a pressure regulator or gauge, how would we determine what psi to set our new expansion tank to? We just replaced the tank and hot water heater.Before replacing them, had an ok amount ...
4
votes
4answers
3k views

Can I install a hot water recirculation pump if I have a reverse osmosis filter?

I'm considering getting a "comfort pump" which will pump water from the hot line to the cold line under a sink so that there is no waiting for hot water, as well as saving the wasted water. My ...
2
votes
1answer
2k views

Why won't my gas water heater light?

Everything was working last night but no hot water this morning. Things I have checked: gas supply to the house is fine electricity is going to the boiler fuses are good sounds like the water pump ...
0
votes
1answer
344 views

Can I repair the floor in the water heater closet with an old street sign?

Can I use an old aluminum road sign as a replacement floor for my hot water heater closet? The old floor is rotten and has some give to it right where a portion of my hot water heater sits, and my dad ...
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vote
2answers
4k views

How can I stop the boiler from heating the radiators when only hot water is wanted?

I have Baxi Boiler (model unknown at this precise moment in time) which British Gas have fixed up to a seperate control panel (see image - not our actual panel, image from Google!). The problem is ...
1
vote
1answer
291 views

Replace under warranty Bradford White or get a new Rheem water heater? [closed]

I have a Bradford White water heater that is about 4 years old, still under warranty, and has started leaking. My understanding is that it must be replaced. The plumber I contacted about this told ...
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vote
2answers
222 views

Can I replace my oil-based water heater with several electric ones?

I was looking at this question, which is somewhat related to mine but didn't give me a good answer: How to evaluate the suitability of an electric tankless water-heater Basically, my mom's water ...
6
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2answers
1k views

How to install Water Heater drain pan to sump pit?

I want to replace my electric water heater. The current water heater does not have a drain pan. I'd like to add one with my new water heater. This is all in the basement. Our basement does not ...
2
votes
1answer
176 views

What to look for in a new water radiator?

The water radiators I have under each window are 50 years old, and I would like some new ones. They measure HxLxD 50x100x20 cm. The new ones I would like should be as thin as possible. I live in an ...
8
votes
1answer
160 views

How to evaluate the suitability of an electric tankless water-heater

I'm trying to evaluate if an electric tankless water-heater would be suitable for my home. There are just too many variables to consider, and I wonder if there is a mathematical approach to it. I'm ...
4
votes
3answers
2k views

Should we turn our oil hot water heater off every night?

My husband and I are considering shutting off our hot water heater from 8pm to 8am every night to save on energy. Is such a time frame long enough to create a noticeable difference in our oil bill? ...
4
votes
1answer
734 views

What could cause a clicking noise in an electric water heater?

I get clicking sound from our electric water heater as well. it lasts for a while, then stops...then starts again, etc. we recently had technician out who said it needed to be cut back on the setting ...
3
votes
1answer
483 views

Can I reuse cold water copper pipes for hot water?

I have a segment of copper pipe for supplying cold water to my gas heater currently. It runs inside a wall so I don't want to replace it. Now I need to change the piping and want to reuse that ...
2
votes
2answers
7k views

After installing expansion tank, massive buildup of pressure then a trickle?

I am completely stumped. You guys helped me out a lot with my previous question here: New gas water heater dripping relief valve, have expansion tank, what gives? Turns out the expansion tank ...
2
votes
1answer
309 views

What could cause the hot water not to work after replacing a water heater?

I replaced my hot water heater and now the hot water doesn't run in any of my faucets. What could be the problem? I did not have to replace any piping from old hot water heater and the water ran fine ...
0
votes
0answers
269 views

Running Shower Faucet After Hot Water Heater's Off

I was awoke by a chemical smell from my electric hot water heater. The past two weeks I noticed my shower was not getting/staying very hot during my 10 minute showers. Thinking not too much about it, ...
2
votes
1answer
628 views

No hot water, but exhaust blower running continuously

This morning I went to take a shower and there was no hot water. I went to the basement to check on the water heater, and found the exhaust blower is running continuously but no hot water is being ...
3
votes
2answers
629 views

What does the low pressure light on my Rinnai tankless water heater mean?

We have a Rinnai tankless water heater in the basement. Our housemate has a bathroom in the basement. About once a week, the water turns cold during her showers or when she uses the sink. We have no ...
5
votes
4answers
521 views

Replacing a hot water heater: tank or tankless?

We've lived in this house for 20 years and the hot water heater (tank style) was 2 years old, as was the rest of the house, when we moved in. In the last year or two we've started to have occasions ...
2
votes
1answer
1k views

Is corrosion on top to an otherwise working electric water heater dangerous?

I moved into a house with an electric hot water heater. The heater is old (11 years) but works just fine. However, the top of the tank has extensive corrosion, especially around the connections for ...
3
votes
1answer
2k views

What could be causing water to drip from the relief valve of my new gas water heater?

My old hot water tank met its maker about two or three weeks ago, and since then I have installed a new Kenmore 50 gallon gas water heater to replace it. The new water heater seems to work fine, I ...
3
votes
3answers
13k views

How do you know when you need a new water heater?

Our hot water is hot sometimes, but not always. For example I might be able to fill up a tub with hot water one morning, but the next morning the water might be cold. This is our first home and when ...
5
votes
3answers
2k views

Are hot water returns worth putting in?

Once I saw on an episode of This Old House that they were putting in hot water return lines: pipes that recirculate idle hot water back to the heater so you get hot water right away, instead of ...
4
votes
1answer
3k views

Are galvanised steel pipes suitable for supplying hot water?

I am living in an old building where the old galvanized steel pipes are still in use indoors. Rather than upgrading to copper pipes, can I reuse these galvanized steel pipes for hot water (from a ...
4
votes
1answer
3k views

Why won't my water heater stop filling?

I noticed tonight that my water heater appears to be trying to fill with cold water, but it won't stop. I can hear water flowing through the pipe, and the overflow drain pipe (white one just above the ...
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vote
2answers
477 views

Sizing DHW expansion tank for tankless heater

I have a combined boiler for hydronic heating and DHW. Earlier in the winter, I started insulating as much of the pipes I can easily access. This has led to hot water coming out of the cold water ...
0
votes
1answer
941 views

Why did my hot water stop?

I have a Rinnai RL94 tankless water heater. Today something went wrong and now I have no more hot water. The machine is not showing any kind of error code like it has in the past when things went ...
2
votes
3answers
6k views

What is causing my gas water heater to squeal?

I have a gas water heater. Starting yesterday, when the flame is on, the unit makes a squealing noise of moderate volume. The noise stops immediately when the flame turns off. This means it is not ...
3
votes
1answer
819 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 ...
3
votes
1answer
2k views

Water heater builds up excessive pressure only when reheating the tank. What's going on?

The pressure release valve on my water heater will trip predictably after a significant amount of hot water has been used (e.g. dishwasher, laundry, long shower) releasing 16 oz or less of water. It ...
2
votes
2answers
1k views

What could cause a new pressure release valve to drip water?

Installed a new pressure release valve on electric water heater because old valve was dripping water on floor. New valve also dripping water. Any ideas? Suggestions? Water temp set at 110F, so it's ...
1
vote
2answers
14k views

What can cause an electric cold water heater to stop working?

Last night my electric cold water heater stopped working and I'd like to figure out whats wrong with it before going off and calling a repair service. What are some things I can do to troubleshoot ...