How to Diagnose and Repair a Leaking Water Heater | Ask This Old House

Ask This Old House plumbing and heating expert Richard Trethewey finds a solution for a water heater that recently started leaking.

Time: 3-4 hours

Cost: $100

Skill Level: Moderate

Tools List for Repairing a Leaky Water Heater:
Bucket
Flathead screwdriver
Pipe cutter

Shopping List:
Expansion tank certified for potable water
Quick connect T fitting
Quick connect ball valve
Quick connect elbow
Quick connect female adapter
Copper pipe

Steps:
1. If there’s a leak at your temperature and pressure relief valve, first test to ensure it’s operating correctly. If it isn’t working properly, replace it.
2. If the T&P valve is operational, check to see if you have a pressure reducing valve, usually near the main water shutoff. If a pressure reducing valve or other form of check valve is present, you’ll need to add a potable expansion tank.
3. Shut the water off at the water main.
4. Using a bucket, drain the hot water heater just enough to get below the pipes and the top of the tank.
5. Use copper pipe and push fittings to connect the expansion tank.
6. Cut the cold water line above the tank using a pipe cutter, then push both ends of the pipe into both sides of the push T fitting.
7. Turn the water back on.

Resources:
Richard added a potable water rated expansion tank to the water heater, which is available through plumbing supply companies.

About Ask This Old House TV:
Homeowners have a virtual truckload of questions for us on smaller projects, and we're ready to answer. Ask This Old House solves the steady stream of home improvement problems faced by our viewers—and we make house calls! Ask This Old House features some familiar faces from This Old House, including Kevin O'Connor, general contractor Tom Silva, plumbing and heating expert Richard Trethewey, and landscape contractor Roger Cook.

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How to Diagnose and Repair a Leaking Water Heater | Ask This Old House

[thefrontierlarp]

This is probably the most clear cut organized "how to" video I've ever seen. Very information, excellent explanation of how everything works.

[DordiHOTS]

Richard and his cutaways. This man knows more than you could learn in a lifetime.

[ZacharySolano]

What’s your superpower?

Richard “Everything I touch becomes a cutaway”

[gyver]

I love his cutaways best part of the show very informative.

[RogerWakefield]

Don't forget to check the pressure on the tank and make sure that you don't install the tank where you cant get to the schrader valve to apply proper pressure if you need to.

[robertcherry]

Believe me Richard knows what he is doing.There is a time and a place for a push fit fitting, and if you listen real well and can read between the lines, he hints at why he chose a push fit for this instance.I have seen them used on commercial multi unit water heaters and still leak free after 12 years.

[lpwnage]

Makes a lot of sense, a lot of things start to leak after retirement...

[tomfitzgerald]

Richard: Why is this happening now?
*Customer rubs chin to show he's thinking*
Customer: Gosh, I don't know if this is it but...
Richard: You may be on to something! Let's explore that.

^^ Completely natural conversation.

[rawbacon]

Richard could start his own Cutaway Museum.

[DavidEvans_dle]

I sure wish there was videos like these on home repair, when I've my house in Newark. But I'm thankful they exist going to have to do most of the work myself at my new home.

[youtubeaholic]

Fixing it is easy. Diagnosing the problem is what takes experience.

[Gears.and.Gadgets]

Nice video. I would never have thought about an expansion tank.

[Iamtheoverlander]

I’ve been explaining it this way for years to my customers and always get a deer in the headlights look at me, sure would be nice to have cutaway views of the parts to help better explain the stuff. Really simplifies it.

[wodentoad]

This is hilarious. Our water heater overflow valve just gave up the ghost at 3am last Monday. Plus side, with the tank still in good repair, we have replaced both heating elements, both thermostats, and the valve. It is like a new water heater.

Someone needs to make a calendar or app that alerts us to all those things homeowners have to do every year for those of us who are new at homeownership. No one taught me about replacing the lower air filter or when to drain the water heater etc.

[Hearthman]

The point he cut in is upstream of the WH shutoff, which means he had to rely on the shutoff at the meter. If that was bad and not holding, rather than go through replacement of that valve and possibly having to shut it off at the curb, he used push-fit because you can't solder with water trickling. They are approved and the owner can always pay to have them replaced if he's worried about them. These fittings will allow that tee to swing so the tank can be brought around for service. Good to see the isolation valve to the tank. You can't check the tank or charge it while pressurized with water from the system. You do need to measure the house pressure then charge the tank to that pressure, which he might have done off camera but should have mentioned it because its the #1 reason for failure of diaphragm tanks. Expansion tank should have been installed yrs ago when PRV was installed. High pressure major cause of indoor 'flood' damage. This is why IPC allows 80 psi max. for domestic water.

[MassEffectFVR]

Shark bites!!?? Come on Richard I've seen you solder like a champ ... Must have been a Friday afternoon service call

[armandoestrada]

This was the most informative video yet! Wow so awesome!
We just bought a home had inspected done, and heater was fine no leaks all. Family moved out, now T&Pv drips, occasionally but it does. So my property helper placed a bucket underneath. There is an expansion tank above so that is covered. Why would it still drip here and there? Couldnit be, no one is living there yet and using the heater?
Heater is about 6 years old already. Should we lower the heater’s temperature? Thanks for any advice.

[AaronRiegel]

Very well done! I learned a lot investing a short period of time

[jasonsgroovemachine]

"Let's take that for a ride for a minute."

I like that.

[plusblood]

Makes a lots and lots of sense
A huge flaw in the water heaters
There should be a thermostatic
Control valve built into
The plumbing associated to the
Water heater side that should be
Automatic
It should stop the heating or water
Entering the system
Or a pressure release valve to
Reduce build up
Huge flaw.