Water heater low pressure

[Shran]

Need input from a plumber, anyone on here?

Have lived in my house for 7 years. Water heater (natural gas unit) replaced in '15 when I bought it because it was leaking. It leaked again around the bottom of the tank in 2018 and was replaced under warranty. Now, I am having issues throughout the house with really low hot water pressure (cold is fine.) Additionally, the latest water heater is dripping out of the pressure relief valve - probably about a quart a week or so for the last month.

I have drained and flushed it a couple times as I hear that sediment can build up and plug the hot side. Thus far that has not helped the pressure issue, but it is no longer making popping noises when the burner is running so I guess that's an improvement.

Any ideas? Rather not replace the whole thing if I can avoid it. Richmond water heaters seem to be junk.

 

[scotts90ranger]

There is most likely a bottle neck after the heater, if there are any steel lines after the heater but before other stuff, probably about to rust shut... at work the water pressure across the board was dismal, but the gauge at the pressure tank read fine and the pump cycled... called a plumber and they found a pipe about a foot long next to the pressure tank that had nearly rusted shut and was about to bust...

 

[Shran]

That thought crossed my mind too. I do not have any steel pipe, most of it is copper and the rest is PEX, and a lot of it is only a couple years old. I had to run new pipe when I remodeled the kitchen & bathroom directly above, and everything within about 5' of the water heater itself was replaced in '18. You'd think if there was an obstruction I could narrow it down but every single hot water source in the house, upstairs and down has really low pressure.

I am concerned that I just let the sediment build up so far that it's just not coming out at this point. It was popping pretty good before I drained it the first time. I'm tempted to remove the hot side pipe and run a wire or something down inside the water heater to see if I can break it free. I don't know if it goes straight down or not though.

I'm pretty bad about not draining water heaters regularly but the one in my previous house dated back to 1992 and I never did anything to it. I bet it's still working fine.

 

[franklin2]

If you had a obstruction in the line somewhere, the hot water should initially spit out pretty good for a second or so, and then dwindle down afterward.

Do you have city water or a well?

 

[Uncle Gump]

All I can add is I'm not a fan of Richmond (Rheem). Two years on our water heater and needed a new gas valve... burner... and pilot assembly.

 

[James Morse]

I have Mertland electric hot water heater it is so old. It was about half full of sediment when I moved here about 10 yrs ago, cleaned it out, replaced one element, it's been good since, knock on wood.

It was made in Chatanooga here is obit of the guy who had the company, who died some 60 years go so figure it's at least that old.
MERTLAND HEDGES, MANUFACTURER, 49 - The New York Times (nytimes.com)

If tank doesn't leak, elements & t-stats can be replaced, and there really isn't much else to them so absent tank corroding through it should last "forever".
Mine says it has anodic rod, I did not replace it.... I think that's supposed to help with the sediment. Not sure what it is or if I can get it. Seems to work without it. Should I try to get one and put in?

I realize this helps you not at all. On mine I believe I could get inside the thing when the element is out, I know I cleaned a ton of crap out of it. You have gas so... is there no way to get to the inside of the tank?

To me flushing won't get out deposits unless it's minor, you have to dig them out. Maybe there is something to dissolve it like CLR etc. Perhaps just a lot of vinegar. Maybe you can get wet-vac suction to it see if that pulls anything out. If you can get to it.

Will be interested to know how it works out.

 

[Mike92STX]

This will sound like a stupid comment but what about the screens on your faucets, if you had sediment, it could have collected on the screen in the faucet.

 

[James Morse]

Not stupid at all it's easy to overlook the simplest things.

 

[Jazzer]

If the aerator screens were blocked, the cold water pressure would be affected as well.
I’d turn off gas, release pressure, and remove hot water out pipe and check it and the outlet as you suggested. Water heater hot outlets draw from the top of the tank, so sediment isn’t usually the problem there. The dip tube on the inlet side could have fragmented and caused a blockage, though.

-Jazzer

 

[Roert42]

The mixing valve in the faucet can also get clogged with sediment and plug only one side. One side is fine and little to nothing in the other.

Have you had to shut the water off to do any work recently?
A sudden inrush from the water being turned back on can break loose anything that was built up on the walls of the pipe.

 

[franklin2]

I have Mertland electric hot water heater it is so old. It was about half full of sediment when I moved here about 10 yrs ago, cleaned it out, replaced one element, it's been good since, knock on wood.

It was made in Chatanooga here is obit of the guy who had the company, who died some 60 years go so figure it's at least that old.
MERTLAND HEDGES, MANUFACTURER, 49 - The New York Times (nytimes.com)

If tank doesn't leak, elements & t-stats can be replaced, and there really isn't much else to them so absent tank corroding through it should last "forever".
Mine says it has anodic rod, I did not replace it.... I think that's supposed to help with the sediment. Not sure what it is or if I can get it. Seems to work without it. Should I try to get one and put in?

I realize this helps you not at all. On mine I believe I could get inside the thing when the element is out, I know I cleaned a ton of crap out of it. You have gas so... is there no way to get to the inside of the tank?

To me flushing won't get out deposits unless it's minor, you have to dig them out. Maybe there is something to dissolve it like CLR etc. Perhaps just a lot of vinegar. Maybe you can get wet-vac suction to it see if that pulls anything out. If you can get to it.

Will be interested to know how it works out.

He has a gas water heater, so no elements.

The anode rod is screwed into the top of the water heater. It looks like a ordinary pipe plug, but once you take it out it has long metal rod made onto it hanging in the water made out of a soft metal. This rod is supposed to be a sacrificial metal that corrodes instead of the tank corroding. The house I live in now and the previous house I had to take the rod out and take a hacksaw and cut it off. In certain types of water (high iron content) it can cause the hot water to smell like rotten eggs. I would rather replace the water heater every few years rather than smell rotten eggs when I turn the hot water on.

The one I am using now with the cut anode rod is going on 7 years old. Not leaking yet and no rotten egg smell either. You can I think get a anode rod made out of a different type of alloy that resists the smell, but I never went to the trouble to get one.

 

[Shran]

I'm on city water. It is not super hard either, probably about average... have seen a lot worse. I do not have a water softener.

The faucet screens crossed my mind as well but everything does it, even the washing machine (no screens in the hoses.) And the cold water pressure is totally fine throughout the house.

Once in a great while I get a nice quick blast of water when I turn the hot on but very rarely. Usually it's just about half pressure right away.

Maybe I will start by draining the water heater again and see if I can shove something through the Out side pipe. I need to check my expansion tank too and see if it's still got air pressure in it - allegedly that's what caused the pressure release valve to leak before because I didn't have an expansion tank. Rheem/Richmond tech support told me to add one and I did and it stopped the leaking valve for about 3.5 years. I guess the air I put it in it could have leaked out? Wouldn't lower the water pressure though.

 

[franklin2]

They are correct, my Dad had the same problem with the water heater pop-off leaking. As the water gets hot, it expands. It needs a place to go. On a well system they have pressure tanks which give it a place to go. You have a pressure regulator from the city, it will not bleed off excess pressure on your house side of the regulator. So the pressure builds up too high, and the pop-off relieves it and pukes water on the floor. If you let this go, the pressure relief can start leaking all the time, especially if it gets a piece of dirt caught in the seat.

Your expansion tank is just a tank with a bladder in it. it has air pressure behind the bladder. The bladder just keeps the air and the water separate. As the pressure rises, it pushes against the bladder, compressing the air and holding the pressure down to a reasonable level. Once you open a faucet or the water temp stabilizes, the pressure will drop back to the setting on the city water regulator. You might want to check your pressure, the city water regulators can go bad or get dirt stuck in them also.

 

[Eddo Rogue]

I have good hot water pressure and low cold water pressure in the house, strange but works for my needs.

My pressure relief valve kept going off, replacing the main pressure regulator fixed that.

Anyways sounds like a blockage somewhere, can you backwash it somehow? might dislodge sediment.

I am really just posting to follow this thread. Water heater diagnosis/repair knowledge is good to know.

Happy New Year!

 

[RobbieD]

I need to check my expansion tank too and see if it's still got air pressure in it - allegedly that's what caused the pressure release valve to leak before because I didn't have an expansion tank. Rheem/Richmond tech support told me to add one and I did and it stopped the leaking valve for about 3.5 years. I guess the air I put it in it could have leaked out? Wouldn't lower the water pressure though.

The bladder in your expansion tank may torn or separated, causing a partial blockage of the cold water into the heater.