What is the easiest way to bypass the coolant circuit from the thermostat to the water heater and back. Without getting into the specifics the water heater has failed and I don't want to replace it until the end of the season, so I'm looking for the easiest way to just remove that circuit temporarily. Could you just install a small loop of 5/8" inch hose between the two connections on the thermostat housing?
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Erik
Chicago, IL
C-36 MK II #2106
Without knowing the engine and the hose routing, its hard to say. But I'd trace the points at the engine where the feed hose goes off to the heater and the return hose comes back, and bridge it with the appropriate length/diameter of hose. Make sure you "burp" the systemn once you do that to get any trapped air out.
The older MkI models (such as ours) came with a complicated arrangement of gate valves at the rear of the engine (over the tranny) to bypass the heater if needed. Many owners (us included) removed them as they just added complexity and took too much space.
Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY
Erik, why are you trying to bypass the coolant. What is the problem with the water heater? It is not likely that the heating coil has developed a leak. If you see coolant around the water heater it is more likely to be leaky hose or hose clamp. Try tightening them. I had similar problem. To access the heater antifreeze hoses remove the cabinet under the sink. If you need to by pass them, remove the hoses and connect them to each other with 5/8" male to male copper fitting.
For smaller loss of antifreeze at the engine connection unplug one of the 90 degree hose and plug in to the other side bypassing water heater hoses.
Haro.
See my website on my signature for photos and water heater replacement and hoses on M35B engine.
Sail La Vie 1999 Catalina 36 MKII, M35B-17031, Coyote Point, San Mateo, CA
About Sail La Vie
I had to do this a couple of years ago when my water heater was having issues and I wanted to take it home to operate on it. I just connected the two hoses that connect at the front of the water heater with a hose coupler like the one below. I finished the season fine like this with no issues. The coupler was a couple of buck at Home Depot.
Don Lincoln
"Nancy Lynn"
1993 Catalina MK1.5, Hull 1238
LaSalle, MI (Lake Erie)
Universal M-35AC
The union posted above is the easiest method.
I have heater loop plugged at the engine with no ill effects (espar diesel water heater for hot water/heat). In fact, IMO its more reliable. Removing the circuit eliminates extra leak points and the oberdorfer pump (known to pump less than the sherwood) does not miss a beat (while testing high rpm extended operation).