Hot water

[jamie snodgrass]

hello, i was wondering if someone could answer a couple of questions about my catalina 30It is a 1981 with an atomic 4.It has a hot water heater in the port side lazerette .My first question is do most marine hot water heaters have a thermostat in them?With mine hooked up to shore power it will not shot off, the heating element just keeps on heating until it blows one of the lines off. Shouldnt it shut off after it reachs a set tempature?Also if dont heat the water up with shore power and try to heat it will just the motor i cant seem to get any hotwater at all.The system is raw water cooled only.Any help would be greatly appriciated.Thanksjamie snodgrasshttp://www.onlineebooks.nethttp://www.ps2parts.net

 

[Ted]

Water Heaters

Most heaters do have thermostat (at least for shore power mode), and pressure relief valve (shouldn't be getting hot enough & building enough pressure to blow a hose. Normal set temps are 140 to 160 degrees.The coolant lines from engine (freshwater closed system,with antifreeze) that supply the water heater heat exchanger must be bleed of air, there are bleed valves for this purpose in lazarette near or on heater. This is most common cause for engine not supplying heat. I'll check the books for my '94 C270 and try to clarify in a few days, unfortunately I don't expect to be home till this weekend. My boat has same heater, etc. as yours I believe.

 

[Pat McCartin]

Water heaters

Most marine water heaters DO NOT have a thermostat. I have to remember to shut mine off after 10 min. If I don't the temp/pressure relief valve will blow and discharge hot water in my bilge.If your engine is fresh water cooled you wont be able to heat you water tank. It's not plumbed that way, unless someone modified the system.

 

[Jamie snodgrass]

Plumed for it.

hmm, my system is plumbed for it. There is a tee in the exhaust, one goes to the muffler and one goes to the in on the hot water tank.The out on the hot water goes back to the exhaust manifold on the motor.Looks like it would work, but I am not sure how hot the water gets coming out of the motor.Not sure if its enough to heat the water.Jamie

 

[Bob Camarena]

I have a 1981 C-30

I replaced my water heater a couple of years ago because I got a great deal at a swap meet on an almost new Force 10 heater. Otherwise, my C-30's original heater worked fine both on shore power and with engine (5411 Diesel) heat. I didn't experience any of your problems.I'm not sure about your shore power problem but it doesn't sound safe. As far as engine heating, it sounds like you have a blockage somewhere. Check your feed and return hoses with your engine running at operating temperature to see if you have good, hot water flow back from your heater. If you have good, hot water flow to but not from your heat exchanger might be clogged. Try hooking up a garden hose and back flush it.Given your shore power problem, a replacement heater may be in order.

 

[Pat McCartin]

Jamie,

You have been modified. I'd suspect an air lock in the hoses or heater. With the engine idling take the hoses loose at the heater and make sure there is water flowing at thoes points. The Atomic-4 has a thermostat set at 140deg F.Universal doesn't recomend changing this in a salt water boat. If you exceed 140Deg the salt that is in your cooling water will start coming out of solution.