Water heater preasure released....

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NYSail

NYSail

.
Jan 6, 2006
3,184
Beneteau 423 Mt. Sinai, NY
Hello all....

So this weekend was the first on the boat. Took the boat out for a great sail on Monday; however when we got back (after motoring into harbor) I noticed water in the bilge and realized the hot water preasure release valve was letting water out. Drive back to the slip this morning and same thing happened.
- Brand new last year 6 gallon Rarital with heat exchanger
- Engine temp (Yanmar 3HM35F) at thermostat was 145 degrees
- anti-freeze level up to cap
- water coming out exhaust strong
When I got back to slip this morning, I read the tag on the preasure release value and it indicated it needs to be manually set off once a year to rid of minerals that may have formed, so I did it and released a bit more water.

So where should I begin??
 
Maine Sail

Maine Sail

.
Feb 6, 1998
11,760
Canadian Sailcraft 36T Casco Bay, ME
NYSail said:
Hello all....

So this weekend was the first on the boat. Took the boat out for a great sail on Monday; however when we got back (after motoring into harbor) I noticed water in the bilge and realized the hot water preasure release valve was letting water out. Drive back to the slip this morning and same thing happened.
- Brand new last year 6 gallon Rarital with heat exchanger
- Engine temp (Yanmar 3HM35F) at thermostat was 145 degrees
- anti-freeze level up to cap
- water coming out exhaust strong
When I got back to slip this morning, I read the tag on the pressure release value and it indicated it needs to be manually set off once a year to rid of minerals that may have formed, so I did it and released a bit more water.

So where should I begin??
Click to expand
Water expands when hot. With no "expansion" tank in the system the pressure can build enough to pop a release valve. Theoretically you would pop a pvc hose first but sometimes the T&P pops. They also blow on temp but it sounds like you are below that.. What is the temp & pressure rating of that T&P? Once they blow I usually just replace them. They never seem to seat right after a pop.. Any plumbing supply house will stock that T&P or can order it for 1/4 of what you'll pay through a marine supplier...
 
NYSail

NYSail

.
Jan 6, 2006
3,184
Beneteau 423 Mt. Sinai, NY
I figured that would be my first item to change..... Just odd that it did pop. What about manually releasing like the "tag" said? Is this a maintenance item I have been forgeting to do?
 
Ralph Johnstone

Ralph Johnstone

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Jan 4, 2006
7,650
Hunter 310 West Vancouver, B.C.
Just for a Quicky Check .................

................. try lifting the valve stem handle and letting it snap back into place a couple of times. You may have a bit of dirt between the valve seat and disk and this may dislodge it.

If not, time to replace.
 
RichH

RichH

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Feb 14, 2005
4,773
Tayana 37 cutter; I20/M20 SCOWS Worton Creek, MD
Simple Rx to keep the PRV valve 'working' and not leaking:

When you open the hot water tank PRV during tank draining for preparation for long term storage, dont leave the PRV valve 'open' all winter. Instead drain the tank with the PRV open and when finished, close the PRV. Any crud on the 'seal' of the valve will force the rubber, etc. to 'accept' any irregularities on the sealing surface over time.
This also applies to spigots and faucets. .... close them 'tight' after draining the system !!!!! .... houses too. Closing of these sealing surfaces will also prevent these surfaces from developing 'scale' deposits when the residual water on the seal eventually 'dries out'.

;-)
 
NYSail

NYSail

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Jan 6, 2006
3,184
Beneteau 423 Mt. Sinai, NY
Changed the preasure release value with a 100lbs preasure value from plumbing supply @$12. Everything appears to be fine.
Thanks all for the input.
 
Bob J.

Bob J.

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Apr 14, 2009
775
Sabre 28 NH
NYSail said:
Changed the preasure release value with a 100lbs preasure value from plumbing supply @$12. Everything appears to be fine.
Thanks all for the input.
Click to expand
Is it a temperature & pressure valve or just pressure?
Price sounds about right but you want to be sure it's a T&P valve.

Reason I ask is most T&P valves are rated for 150 psi, 210 degree's
 
Maine Sail

Maine Sail

.
Feb 6, 1998
11,760
Canadian Sailcraft 36T Casco Bay, ME
Misfits said:
Is it a temperature & pressure valve or just pressure?
Price sounds about right but you want to be sure it's a T&P valve.

Reason I ask is most T&P valves are rated for 150 psi, 210 degree's
Click to expand
Spot on.. If it is a water heater it should be a T&P not just a pressure relief valve.
 
NYSail

NYSail

.
Jan 6, 2006
3,184
Beneteau 423 Mt. Sinai, NY
Yes preasure and temp. It is 100 psi and 210 degrees. Thanks!!
 
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