Pressure relief valve on hot water heater

[Chuck15558]

I have a 2001 Beneteau 361 with the standard 6 gallon hot water heater under the starboard settee. When underway with the engine running and the water system pressurized (i.e., freshwater pump on), the hot water tank pressure relief valve on the tank will open after a time and allow freshwater to flow into the bilge, emptying the water tank that is feeding the system at the time. Coolant level in the engine (Westerbeke 30B THREE) is okay and it doesn't seem to be running hot. The water flow from the hot water tank relief valve lessens if I turn the freshwater pump off, but the valve still cycles and releases some water. I think the hot water tank relief valve may be bad, but do not want to replace it until I have checked with other owners. It does not seem to be normal that the engine hot water heat exhchanger would heat the water hot enough to open the pressure relief valve.Thanks.

 

[Rick I]

Sounds like a faulty relief valve

I've heard of this happening on a few Beneteaus.

 

[Bill C320 Papillon]

hot water

This doesn't sound like a Beneteau problem. They don't make the water heaters. Find out what brand the heater is and get in tough with the manufacturer. I don't know how much room you have to work around the heater but if there is sufficient access, replacing the relief valve should be pretty easy and inexpensive.

 

[Rick I]

Bill, go to a few B sites

you'll see that this happens more often than you'd think. I think a new valve is available at most hardware stores. I think it's the same valve that's on your home hot water heater.

 

[Mike]

Not happening on mine

I have an 02 361 and have not had the problem. I too would think it's just the relief valve. Can't think of any other reason it would do it.

 

[Stan21606]

Hull #210

I believe my hot water heater (B361 #210) is from Attwood.Although you're probably right about a bad pressurerelief valve, it seems a bit like saying "it can't possiblybe a fire and then taking the batteries out of the alarm toquiet it down". Have you checked the temperature of thehot water to see if it's excessive? On a home hot waterheater, the pressure can build up if there is excessiveoxidation at the bottom of the tank. Changing out thevalve may be the simplest solution, but I'd do a bitof sleuthing first.

 

[Chuck15558]

Thanks all

I will check out the engine coolant temperature. It does look to me that the pressure relief valve is the same used on a home HWH.