Water Heater

Came home to find water running out from under my house.
After some investigating found a pencil lead size stream coming from the water heater pressure valve.
Opened the valve and let it run for a while and then when I shut it off the stream is as big as a #2 pencil.
So I go inside and fill the tub so at least I can take a bath tonight.
Water seems extra extra hot.
So I go outside and hook a hose to the heater and flush it of hot water.
Now the pressure valve is leaking a drip a second.

I'm thinking one of the two thermostats is stuck on; over heated the water; blowing the pressure valve.
I really hate putting money into this water heater because the serial number says it was built in Sept 1990.
But since a cheap 6 year 50 gallon water heater is over $500 I am going to try and rebuild this heater.
2 new thermostats; heating elements; and a pressure valve.

So my question; are these parts pretty much universal or do I need to buy specific parts that fit my brand heater only???
Anything else I should do while I got it apart????



cvphoto126030.png






cvphoto126031.png
 
It probably only needs the lower element.

What happens, the element shorts to ground, with one leg always hot, it sends 120v through the element to ground, which makes it produce uncontrolled heat.

The pressure valve also reacts to heat, so it was just doing what it was supposed to. Now it may not seal when everything returns to normal but give it a chance, see what happens.
 
Probably pretty much standard parts. Take old parts with you when you go shopping.

Try to clean out as much sludge and scale out of the bottom as you can while you have it down. Might try a wet/dry shop vac and a plastic hose in the port in the bottom. May be able to remove drain valve for access.
 
i would replace both elements and the t and p valve. there are a few different size elements, so pull one of the old ones and match it up. as the others have stated clean all the sludge out too.
 
Some of the older heating elements were a 4 bolt flange mount, you better look at what you have. I would test each element and probably only replace the bottom one if the top is still good, and replace the T&P valve. Some of those tanks can last a long time if they're well made and you have good water.
 
(quoted from post at 19:03:28 05/17/22) It probably only needs the lower element.

What happens, the element shorts to ground, with one leg always hot, it sends 120v through the element to ground, which makes it produce uncontrolled heat.

The pressure valve also reacts to heat, so it was just doing what it was supposed to. Now it may not seal when everything returns to normal but give it a chance, see what happens.

X2 to what Steve wrote.

While not the only possible scenario that can cause overheated water it's the most common, probably an 80% or greater chance a failed/shorted on one "leg" element is causing it.
 
As for your original question, water heater parts are mostly universal. But you should try to find replacements that are as close as possible to what you have.

Any hardware store will have a T&P valve that will work. Actually, the one you show in your post is from an RV parts supplier, that's how universal they are. There is a similar valve for boilers that is pressure only, but you won't find it in most hardware stores.

The heating elements come in a variety of wattages; the actual size of your elements should be marked on the heater. If it's on a 30 amp breaker it can take up to 6500 watts, 25 amps can handle 5500 watts and a 20 amp breaker can only use a 4500 watt element. Often the upper element will be larger than the lower one, since it is used less. Elements come in different lengths depending on the diameter of the heater tank. A skinny heater may need an element that's doubled up to fit in the tank.

When an element fails, it's almost always the lower element because it's the one that is used the most. The symptom of a failed lower element is running out of hot water sooner than expected. When the upper element fails, you won't have any hot water at all.

As I said in my earlier post, I think replacing the T&P valve will fix your problem. You say the water seems too hot, but that may be caused, surprisingly, by the leaky valve. All thermostats have a certain amount of hysteresis, meaning they turn off at a higher temperature than they turn on. The difference may be about 10°F. The leaky valve is preventing the thermostat from turning off, so the water is being heated to almost, but not quite, the shutoff temperature.
 


There can be a lot of variation so check them closely. You need to get the wattage the same. The watt rating is often in very fine stamping on the edge of the metal or molded into the edge of the plastic. As Russ posted they could be either screw in or bolt in. But, as Mark posted your problem could be only the pressure relief valve. It is not unusual for them to go bad. We kept replacements on each truck. But check the BTU/hour rating on the tag. putting the wrong one in won't help you.
 
For the bottom element element I like these as I have hard water.
Sandhog Long Life II Heating Element, 4500W x 240V
https://www.amazon.com/Sandhog-Long-Heating-Element-4500W/dp/B000KKSBY2#customerReviews

The link is just for illustration purposes.

Some people think replacing the sacrificial anode rod is a good is a good idea.
 
Agree with you:
2 new thermostats and a pressure valve.

Only replace elements when they go bad.
Test them with an ohm meter.

They make special elements that operate in sand.

Camco 02932/02933 5500W 240V Screw-In Lime Life Foldback Water Heater Element - Ultra Low Watt Density

240V/5500W
Best when water has high mineral count
Resists dry firing
Heats in lime and sand that would burn out ordinary elements

You may need lower watts.


If your elements aren't broken, why replace them??
 
Good mornin John, hope alls well your way, Ive seen cases where once that valve trips and/or leaks even if all else is fine, they may not seal back fully......You might try just a new valve first and then if there's still a problem (like new valve trips due to high temp maybe ??) check out the t stat and elements and replace what's needed.......

Good luck let us know hot it turns out

John T
 
I will second this advice. I had an issue where the pressure valve tripped and wouldn't seal after the issue was resolved. Replaced the valve and all was well.

Steven
 
They never seem to seal, I tested one once and it failed to reseal. Most modern elements are the same or similar enough to work there are however exceptions. Could be a stuck thermostat also. Everybody always tells me how easy theirs's screwed out, I usually have to use the 3/4 inch drive with a pipe.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top