Hot Water / Cooling System Valve

[Jim Hamilton]

On my '87 Catalina 30, there is a valve that allows engine coolant to circulate around the water heater tank to heat your water when away from the dock. The previous owner of my boat has removed the piping that connects this valve to the engine coolant. This has completely removed the water tank from the loop. While not knowing why this was done (perhaps the valve developed a leak or something) my question is two-fold:How many of you have used your engine to heat your water and what is/are the benefits of having a valve to turn this 'on or off'?? Why wouldn't you simply run the plumbing so that the water heater ALWAYS heated water if the engine is running? I'm debating on whether or not this valve should be replaced and the plumbing reconnected or simply redo the plumbing so that it's always in the loop and the valve removed...Any ideas/comments??JimS/V Jimmy Dreams

 

[Calif. Ted]

Most are as you describe without a valve,

to shut it off. Only advantage I can see would be if the heat exchanger developed a leak you could shut down the flow (would need another on return line). A leak in exchanger may be why previous owner disconnected (most logical thing I can think of) they are similar to a car radiator and can be repaired in similar fashion. You will need a bleed valve to remove air when you change coolant because the heater is usually the high point, I've attached photo of bleed valve located next to heater in lazarette.

 

[Tom Ehmke]

Not sure

why Catalina set up the valve array in the coolant system the way it is laid out, but there it is. I had a major problem with air in the coolant lines this summer (the boat was new to me in June) and after a lot of research and experimenting, I got the air out of the line once and for all (I hope). There is a long story that goes with all of this and I won't bore you with the details, but I discovered how and why the valves work while bleeding the air trapped near the w/h. Maybe someone else can explain the set-up or suggest eliminating part of it, but I'm not that person. One reason that I can think of to bypass the w/h is to temporarily eliminate the air in the line problem if the air is in the w/h loop. Another would be to isolate the w/h if it is broken or if you want to replace it.Hot water was new to me when I bought the boat. Glad I have it now.Tom