The water heater I'm installing is higher than the engine, a Yanmar 3jh5e, and I need to replace the coolant expansion tank that goes above the water heater. The one I pulled out is made from a fiberglass type material, and looks much older than the engine. It's been sitting loose on top of the old water heater since I got the boat. I want to replace it with metal if possible since it's pressurized.
Does anyone know where I can purchase an expansion tank that is right for this? I have spent hours searching the web but have not come up with much. From what I can surmise, the tank should be higher than the heater and have a pressure cap with a lower rating than the one on the engine. What those pressure ratings are, I'm not sure. I've read 14 and 7, and 14 and 13.
Thanks,
Mike
Have you looked at blow molded automotive tanks. I'm using a VW expansion tank on my Westerbeke. I mounted it so I can get to the cap when I open the lid under the companionway. I also went to the extra trouble of connecting the vent hose to the thermostat housing. Helps to burp the motor when I flush the coolant.
Pete
Turns out I'm using a Volvo 760 tank and cap. Not VW as originally stated.
http://www.boatpartsandspares.co.uk/volvo-penta-cooling-system-expansion-tank-1761-p.asp
You'll be happy to know that it's also the same tank used by Volvo Penta on the 2002 marine diesel engine. But if you can get one from a junk yard the mounting bracket for the tank is worth snagging. It comes off with a 10mm wrench.
Pete
I found a tank. It's called a surge tank, as opposed to a coolant recovery tank which usually is made of plastic. The manufacturer is Sen-dure. It's made of heavy metal and comes with a 7 psi cap. The one I got is 3 or 4 quarts, not sure of the exact capacity. Picked it up at a marine service company in Newport,RI that does a lot of re-powering jobs. Now the trick is how to mount it and everything else. All this is going to require some planning and construction. Think I will loop the engine coolant hose back to the engine for now so I can use it and get some sailing in. Some other things to do is to add a thermostatic controlled mixing valve and some sort of manifold system to organize the water lines going to the shower and faucets. This is bigger than a weekend project.
Thanks for all the replies,
Mike