Water Heater Release Valve Issues

[jakez]

I recently acquired my C36 MKII. My wife left the water heater on just after I got it and the release valve popped. I noticed it because my water pump was going without any faucet on. I turned off the pump and let the water drain from the water heater, and once it all cooled down, everything worked fine. That was a couple of months ago.
I was out last weekend under engine power for about 5 hours. I went below to open open the macerator thru hull and noticed that water was coming from black over flow hose off the water heater. I thought it was strange, since the water heater wasn't on. The water was warm. Not long after I noticed my recently filled fresh water tank was dry. I'm not sure if my pump was running - I was on deck for the most part and motor sailing. But I do know for sure my water heater switch was "off".
I'm pretty new to this boat and don't have a great grasp on all of the systems. Does this make sense to anyone / has anyone had a similar experience?

 

[Stu Jackson]

Yes. The heater works off the hot water freshwater coolant when the engine is running, and off electricity when it's not. It's all in the boat manual. If you don't have one, join the www.catalina36.org and get one.

1. Don't leave the power on it more than 15-30 minutes. It'll heat the hot water and last a long time. Turn it back on when you need to. This avoids overheating.

2. Replace that valve. Once they pop, sometimes they don't seat back properly. Take it off, bring it into an ACE Hardware store and buy a new one. get teflon tape, too.

3. Get in the habit of using the hot water faucets even when you don't have hot water. Keeps the water moving thru the heater, avoids the rotten egg smell. http://c34.org/bbs/index.php/topic,5836.0.html

Good luck, we've all been in your shoes.

Nice boat.

 

[jakez]

Thanks as always Stu! I did know the engine supplied HW while running and not on shore power. But, I couldn't figure out why my fresh water tank emptied.
I suppose that the engine warmed water caused the valve to pop and once that happened the open valve kicked my water pump on.