leaking relief valve on water heater

[steve77]

Originally Posted by deluxe68

They put check valves in the input to the water heater for a reason.

Oh? What would this reason be?

[deluxe68]

Originally Posted by steve77

Oh? What would this reason be?

http://www.cruisersforum.com/forums/...ter-97996.html

[steve77]

Originally Posted by deluxe68

http://www.cruisersforum.com/forums/...ter-97996.html

You have a good memory to recall this thread from 2013. However, in this thread there was no consensus that a check valve was required. For every reason that a check valve may be required, there were reasons not to install one.

Silorchic summed it up by saying she would not install one on a boat, and for our plumbing system on our boat, I absolutely agree with her.

Steve

[donradcliffe]

Steve,
To see if you need/want a check valve, get the tank water hot, then open a cold water tap and let it run for a bit. If you find warm water coming out, its maybe time for a check valve.

Another issue that the check valve may affect is the shower temperature fluctuations which come with pump cycling. That one is complicated, and I'm not sure whether the valve helps or hurts. I've had big temperature fluctuations on the boat with a check valve and accumulator, but never had a problem with my house showers, which do not have a check valve. I've been in houses/hotels were flushing the toilet meant the person in the shower gets scalded, but never in my own houses, so I never did anything to fix it.

[steve77]

Originally Posted by donradcliffe

Steve,
To see if you need/want a check valve, get the tank water hot, then open a cold water tap and let it run for a bit. If you find warm water coming out, its maybe time for a check valve.

Another issue that the check valve may affect is the shower temperature fluctuations which come with pump cycling. That one is complicated, and I'm not sure whether the valve helps or hurts. I've had big temperature fluctuations on the boat with a check valve and accumulator, but never had a problem with my house showers, which do not have a check valve. I've been in houses/hotels were flushing the toilet meant the person in the shower gets scalded, but never in my own houses, so I never did anything to fix it.

Thanks. I understand that a check valve will prevent hot water from being drawn back through the supply line to the cold water tap. It's just not a problem that I have. What I DID have was a wet bilge, and removing the check valve solved that problem. I no longer have water dribbling out the relief valve as the water heats.

Our water heater has a tempering valve to control outlet temperature of the water, and it seems to cause fluctuations in shower water temperature. This was with the check valve installed, and the temperature would take a few seconds to stabilize each time I turned the water off and back on as I showered. I have only taken one shower on board since removing the check valve and noticed no difference.

For some boats the check valve may be desirable. Just not for me.

Cheers!

Steve

[GordMay]

Originally Posted by steve77

... I don't know a lot about tempering valves. Is it common for one to incorporate a check valve? ...
Steve

Yes.
Hot Water Temperature Control Valves often incorporate integral check valves in both the hot and cold water inlets to protect against cross flow.

Eg: Watts ➥ Tempering Valves, Backflow Prevention, Watts

[steve77]

Originally Posted by GordMay

Yes.
Hot Water Temperature Control Valves often incorporate integral check valves in both the hot and cold water inlets to protect against cross flow.

Eg: Watts ➥ Tempering Valves, Backflow Prevention, Watts

Thanks, Gord. Makes sense that check valves are incorporated in tempering valves. Appreciate the link.

Steve