Hot water heater problem

[Moon]

We have a 50 gallon gas water heater. On top where the 3/4 inch connectors go into the tank I see a white crystal like build up. The other day I noticed the relief valve had been letting out little bits of water. I could see dried up stains on the floor, and I saw a fresh drip occuring. It leaves a white milky stain on the concrete. Not a well, it's city water and tastes fine.
Any guesses as to what the white stuff might be and how we can stop it?

Thanks,
Moon of Ohio

 

[tc35dforme]

I'd bet lunch that it's the evidence of galvanic corrosion. Dis-similar metals ( ie copper vs steel ) will corrode by means of touching in the presence of a catylist ( water ). You probably have steel nipples on the tank. You should add what's called a di-electric nipple which is just an insulated inert fitting that keeps the two apart.

As for the relief valve, it could just be a case of a dirt particle in there ?

Do you have a check valve on your water main as it enters the house ?? If you do, maybe you have an expansion issue.

Of course, you could just have a bad relief valve .... I'm not sure the two items are related.

Nothing like a reply with questions....huh ?? /forums/images/graemlins/smirk.gif

 

[thcri]

I am going to agree with TC35. I don't know how old the water heater is but having city water doesn't mean you will have a water heater that will last a life time. In parts of our city your water heater will only last 5 years because of build up.

murph

 

[jayhawkRoy]

If your relief valve is weeping, you probably need to replace it. You can try flushing the valve out, but you may end up with a valve that leaks even more. Crud gets stuck around the seal inside, and the valve weeps or leaks. It is hard to get them to stop weeping without replacement. Since you have to partially drain the tank below the relief valve level to replace it, go ahead and replace the inlet/outlet with the dielectric nipples mentioned above, unless you are absolutely sure the ones you have are thedielectric type.

 

[dbelisle]

Most of the time I have found that the fittings on the water heater are leaking , but not enough to see any water . The water evaporates from the heat of the water heater . What you are seeing is the mineral build up from the water over a long period of time .

I would take the fittings off and redue or replace them .

Your leaking relief valve may be just something under the seat or it could be from thermal expansion. The pressure in your system could be getting over 125 Pounds and the relief valve is doing its job and bring it back down.

I don't remember you saying how old the water heater was , but it is recommended you replace relief valves every three years.

Being on a Municipal water system you should have a double check valve where the water line enters the house.

You can get a tattle tail guage to put on your system over night . It will tell you the highest pressure on your water heater when you look at it the next day.

If that's your problem, you can add a expansion tank and your problem will go away.

Dave in NH

 

[Moon]

The tank is a couple years old. We've built new and moved in in Feb 98 and we've already replaced the tank once.
I looked at someone elses water heater on the same water as us and it does not have the build up.
I thought we had a 3/4 " copper fitting going into the tank.

Thanks for the suggestions. Now I gots to do some checking.

Moon of Ohio

 

[johnk]

Sounds like a calcium buildup to me. Does you tank sound like its rumbling when the burner is on?? If the water has a lot of minerals in it this will happen.

 

[PineRidge]

Common water heater problems

Sediment buildup
Water heaters heating of water causes calcium carbonate to precipitate out and settle to the bottom of the tank. Steam bubbles form under the sediment when the burners come on causing popping and other noises.

Regular flushing helps prevent sediment build up.

Not producing enough hot water
Check for a broken dip tube, wrong setting on a thermostat, a defective thermostat, burned out heating elements (electric), or a heavy build up of sediment.

Dip tube
The dip tube is a long slender tube that fits down into the water heaters inlet, and usually has a small hole about 6 inches from the top. The dip tube directs the incoming cold liquid down to the bottom of the tank. If the dip tube is broken, the incoming cold liquid can mix with the out going hot liquid and cause it to seem as though you are running out.

Noisy tank
Noise coming from gas models can often be caused by the sediment build up in the bottom of the tank. Steam bubbles form under the sediment. The thumping and popping noises are created by the bubbles escaping from under the sediment.

Sizzling noises can be caused by condensation dripping onto the hot burner.

Thermal expansion
When water is heated it expands. If the inlet is not blocked by a check valve, pressure reducing valve, or other device, the increase in volume simply travels back into the source. If the inlet is blocked, this increase in volume will cause an increase in pressure, sometimes to dangerous levels.

The T&P (Temperature-pressure) valve relieves this pressure by discharging some liquid. A thermal expansion tank can be installed in the line that will absorb the increase in volume, preventing the relief valve from discharging unnecessarily.

T&P valves are strictly an emergency measure and should be replaced every 2 years. At 180 psi , the temperature that the T&P valve opens, damage can occur to your system and you may have voided the warranty on your water heater.

The improper installation of back-flow preventer's can block the thermal expansion leading to operation of the T&P Valve.

Water Hammer
When liquid is traveling in the pipes it has kinetic energy (energy of motion). When a valve shuts off suddenly a shock wave results.

Hammer most often occurs when a valve shuts off suddenly. Commercial arrestors are available to combat this problem. They consist of a small air bladder within a cylinder plumbed to the piping system near the valve causing the problem. Some hardware stores carry them.

Sometimes if the piping is sagging then supporting the pipe solves the problem.

Milky color
Water contains dissolved oxygen and other gases. When it's heated it has less ability to hold these gases and when the pressure is lowered as the liquid comes out of the tap these gasses can form tiny bubbles giving the liquid a milky appearance. Letting it stand for a few minutes will allow these bubbles to rise out of the liquid and it resumes its clear appearance.