Plumbing question

Legume

I have a water heater that is 10 years old.  Recently the temp and pressure relief valve has started to leak, mostly just a steady trickle.  The internet said they sometimes build up scale that will keep them slightly open, so the suggestion was to flip it open and close several times, letting it slam closed.  Also suggested this may need to be done over several days to clear the build up.  I tried three days, this didn't work so I went ahead and drained the tank and installed a new valve.

The leak remained, so I went through the process again and still it remained, so I can't see how it's the valve.  I then moved on to the 2 gallon pressure relief tank.  I removed the tank and poured the water out. There was no pressure in the bladder and it was holding a fair bit of water that didn't drain, so I figured the bladder failed at some point and was no longer able to take up any extra pressure in the water heater.  I bought a new one, checked the house pressure and pressurized the new tank to match the house pressure.  Installed the new tank and fired the water heater again and set to a lower temp than I normally have it set to and the leak from the temp and pressure valve returned.

My next thought was the thermostat / thermocouple may have an issue causing it to overheat the water.  I checked the temp coming out of the closest faucet and it was 120, so I don't think that's it. I do notice that it's leaking less now than it was when the heater temp was set higher.

What am I missing?  Next steps?

thanks

The Cen-Tex Smoker

Call Bradley lol. I think he will be out here this week anyway. 

Legume

The Cen-Tex Smoker said:

Call Bradley lol. I think he will be out here this week anyway. 

I did the other day, not sure he's actually a plumber 🤣

The Cen-Tex Smoker

Legume said:

The Cen-Tex Smoker said:

Call Bradley lol. I think he will be out here this week anyway. 

I did the other day, not sure he's actually a plumber 🤣

I’m really counting on him to be one though. 

nolaegghead

You can’t see where it’s leaking?  If it’s an NPT joint, use some pipe compound or Teflon tape and tighten it as much as you reasonably can, make sure you don’t bottom out the threads, add more tape/compound so that doesn’t happen.  If the female NPT bulkhead fitting on the tank is cracked or leaking on the weld, buy a new unit.  Might get a prorated exchange on the warranty.

Legume

nolaegghead said:

You can’t see where it’s leaking?  If it’s an NPT joint, use some pipe compound or Teflon tape and tighten it as much as you reasonably can, make sure you don’t bottom out the threads, add more tape/compound so that doesn’t happen.  If the female NPT bulkhead fitting on the tank is cracked or leaking on the weld, buy a new unit.  Might get a prorated exchange on the warranty.

It's sealed, the leak is actually water release from the valve.

kl8ton

Is it a gas water heater?  Hurry and buy a new one before the government and "big appliance" bans them!

My own limited experience.... It's at its end of life.  I chased these things on one heater only to have main tank develop a leak two months after I fixed pressure relief valve and 6 months after fixing the drain valve.

SGH

If I’m understanding what you are saying the PRV is not seating. Have you tried replacing it?

Legume

The black market for gas appliances will be huge when people price out adding 240 where they don't have it.

Legume

The PRVs are all acting like temp or pressure is opening them, but just a trickle.

Legume

SGH said:

If I’m understanding what you are saying the PRV is not seating. Have you tried replacing it?

Sorry, didn't answer both questions.  Yes, replaced the original and it leaked.  Bought a second replacement and that leaks too.  Three valves all doing the same thing, so it's not the valve.  Guy at hardware store said he's never had one come back for failure, so while I'm sure it happens, it's rare enough that I couldn't have had two new ones both fail.

SGH

I’m not a pro plumber by any means, but if 3 different prv’s are bypassing it sounds like somehow you are getting a overpressure. Proceed with caution my friend. And good luck. 

Ozzie_Isaac

I would remeasure your line pressure to the water heater, then confirm your expansion tank is pressurized correctly.  If it all seems correct, I would bump up the pressure a little and watch the leak for a heating cycle.

Legume

Ozzie_Isaac said:

I would remeasure your line pressure to the water heater, then confirm your expansion tank is pressurized correctly.  If it all seems correct, I would bump up the pressure a little and watch the leak for a heating cycle.

Bump the pressure in the expansion tank?

SGH

If your prv is like this one:

If it is put a bucket under it and hand trip it for about 3 seconds. I have seen that make them seat before. If that don’t work I’m going back to what I said earlier. Somehow you are getting over pressure. Just not sure how.  

SGH

This almost goes without saying, if you hand trip it be very careful. It will blow like the devil.  

Legume

SGH said:

This almost goes without saying, if you hand trip it be very careful. It will blow like the devil.  

I'll try that again. It has a 3' section of copper running down the side of the tank and I have fitted a poly flex line to that so it empties into a floor drain.  This is the only valve that I didn't hand trip yet, worth another shot.

Legume

10 year old water heater, I sincerely hope it hasn't gone bad already.

Ozzie_Isaac

Legume said:

Ozzie_Isaac said:

I would remeasure your line pressure to the water heater, then confirm your expansion tank is pressurized correctly.  If it all seems correct, I would bump up the pressure a little and watch the leak for a heating cycle.

Bump the pressure in the expansion tank?

Yes, bump the pressure in the expansion tank a little.  I am wondering if you are still bottoming out the expansion tank.

kl8ton

Legume said:

10 year old water heater, I sincerely hope it hasn't gone bad already.

Current life expectancy is between 8 and 12 years.

kl8ton

A while back I believe water heaters lasted upwards of 20 years.

RRP

Legume said:

10 year old water heater, I sincerely hope it hasn't gone bad already.

Honest…my 12 year unit blew this Summer after 11 years. At my age of 78 I popped for another 12 year assuming the next gas hot water heater will be QUITE EXPENSIVE…but most likely somebody else’s problem - or I haven’t seen the ball since kick off anyway! 

kl8ton

The house I just bought was built in 2015. The home inspector said the water heater is original. It's probably best to just replace it when you move in.  

Legume

I don't think I've had a water heater last less than 15.  I hope that's not it.

House pressure is 75psi at the hose bib.  One of the reasons I'll
probably get a plumber anyway, that's too high and I would like for him bring that down where it enters the house.

alaskanassasin

Yep I dunno there is something definitely going on though.  If I were in your shoes I would want to to know the pressure in the tank and how to troubleshoot the pressure tank on top.

Botch

A more general question: does a water heater get noisier as it dies?  Mine starts banging, gurgling, rattling and farting, so loudly anymore that it wakes me during the night.  
I've lived here 28 years, and know I've replaced it once, but I don't remember exactly when.  

kl8ton

Legume said:

I don't think I've had a water heater last less than 15.  I hope that's not it.

House pressure is 75psi at the hose bib.  One of the reasons I'll
probably get a plumber anyway, that's too high and I would like for him bring that down where it enters the house.

Well or Municipal?  Sorry if that has been answered.

Legume

Municipal 

Roadpuke0

The pressure on the expansion tank to me is off or the tank is to small. Thermal expansion is what is causing the t&p to drip. A plumber can install a pressure reducing valve to-reduce you incoming pressure if need be. You may be setting the expansion tank pressure from a reading you take but line pressure changes all the time if it is a public line. Anything over 8 years on a heater these days is a bonus. 

alaskanassasin

do you have a pressure guage

Botch said:

A more general question: does a water heater get noisier as it dies?  Mine starts banging, gurgling, rattling and farting, so loudly anymore that it wakes me during the night.  
I've lived here 28 years, and know I've replaced it once, but I don't remember exactly when.  

I had one that would do that when the water softener was getting low on salt, in other words it was caused by hard water.

Legume

@Roadpuke0 thanks.  2 gal pressure tank for 50 gal water heater - said it's the right size on the manufacturer's spec.

Plumber just emailed, working out a time to have him swing by.