Water Heater has air in it.

[Butch5220]

I think it is an Atwood. It's 12 gallon and is plumbed with the cold water entering at the bottom. After fixing several leaks I tried to bleed the system but there seems to be air trapped in the water heater. The water pump takes a long time to shut off after running the hot water faucets. If I run just the cold the pump shuts down almost immediately after turning off the faucet. If I jumper the two lines going into the heater the pump shuts off quickly after turning off the faucet. I have also tried bleeding the relief valve but that does not help. The water heater does make hot water.
Perhaps this is normal but it does not seem right to me.
Any input would be helpful.
Thanks in advance,
Hankster

 

[Texasmark]

Re: Water Heater has air in it.

Not familiar with your device, but familiar with the physics involved, any air in the system would make for sloppy shut off performance if the valve is pressure (not temperature) sensitive. Surely the hot water heater, as compared to a directly plumbed cold pipe would offer the opportunity to include trapped air. Rocking the boat side to side, or fore to aft might help to rid you of the air.....but, if air is included in the cold water inlet in a short time, there would be air in the system again.

I had a deep well pump once that supplied water to my farm. I had a pressure tank that had a pressure shut off. Periodically, the tank would fill with air, that it got from the water inlet somehow, and the control valve would act in a peculiar manner, not shutting off as it was supposed to do at a given pressure.....couldn't reach the pressure because of the compressible air in the system.
Draining the system and refilling with well water would solve the problem for a couple of months and then it would do it all over again.

HTH,

Mark

 

[Thalasso]

Re: Water Heater has air in it.

deep well pumps work diff. you need pressure in tank to run the high low shutoff valve.Used to have one.No air pressure tank gets what is called waterlogged. boat tank is diff.turn on shore supply .Open the relief while shore water is on.Run to there is no more air. Don't open drain valve I think it's more like when you fill your home water tank

 

[steelespike]

Re: Water Heater has air in it.

If the pump is sucking a little air it will accumulate in the tank.And in a hot water tank
air can be released as the water warms.
In the old style domestic system tanks in a proper working system they would eventaully
become water bound and short cycle.
At the cottage the hot water would occasionaly have a small amount of air in the tank.
It would burp a few times and be ok.Unless yours is drawing air somehow it should bleed out.