Trojan Boat Forum

My all electric water heater needs to be replaced. I am looking at Attwood, Seaward and Kuuma 11 gallon electric heaters with heat exchangers. Does anyone know where to tie the water lines into the engine cooling system. I have a 1981 Trojan international with Crusader 270's closed cooling systems.
There are 2 capped ports on the thermostat housing but not sure if these are in and out.

Well I am going to go down the same route and have researched here and elsewhere a while back. On a 318 Chrysler, which I feel water flow will be the similar, hot water goes out of intake manifold to water heater heat exchanger then back to inputs on top of circulation pump. I verified this by looking up the automotive heater core hosing and that is the way it circulates so should be the same to water heater. I would look up a heater core circuit for a plain old chevy car or truck engine in your case.

Interesting the Chrysler 318 has two threaded outputs on the intake manifold both have senders one fore water temp and one for over heat warning. Either should sense the water temp in a brass tee if installed and still function properly. A tee would give me a place for a hose barb to the hot water heater.IMO

See if there is a plug on the water pump and on the front of the intake manifold . Beware too much flow through the water heater can cause over heating as you are by passing some flow through the heat exchanger . This can take a long run to show up ,just keep this mind .



Larry be careful putting a temp sender in a tee , you could get a air pocket around the sender and id may not pick up true temp

Thanks, I will check the pump and intake for plugs.

A few ways to skin this cat. Some run off the t-stat housing, circ pump, intake manifold. Volvo sometimes runs one end off a block drain, Merc sometimes runs one end off the large circ pump hose - they have a special T fitting for this.

prowlersfish wrote:....Beware too much flow through the water heater can cause over heating as you are by passing some flow through the heat exchanger . This can take a long run to show up ,just keep this mind .

Larry be careful putting a temp sender in a tee , you could get a air pocket around the sender and id may not pick up true temp

+2

thanks for the great information.

Just curious how many people hook their water heater up to the engines? Mine is currently not hooked up but I have considered it. Prowlersfish brings up a good point about . any other downside to doing it?

I intended to post a diagram from Chrysler how the 318 is hooked up in a car to the heater core. I will but not on this computer. The two return ports available available on the top of the circulation pump are small threaded ports and should of and in themselves create a restriction to too fast of water flow. Regardless if a cavitation should occur the sensor not in the tee should work, either the temp sensor or the overheat alarm sensor. One would think the water flow would carry air bubbles on through, but one should watch the temp until sure. Outside of using a tee for sensor one would have to drill and tap the top of the manifold and there is no third boss cast in the manifold for such a function. Check the below URL suggests using a temperature valve on the return side.

http://www.marlow-hunter.com/export/Ven ... Heater.pdf

You could install a tempering valve

++ on tempering valve

I tried to attach 318 heater hose flow as a PDF but no luck, anyone know how to do it, Apparently the extension PDF is not allowed.