snip


In thinking about it you could plumb in a 3/8" valve at the engine
outlet and open it when you wanted to make hot water, in fact it is a
good idea..

I had a electric/calorifier hot water tank, perhaps 20 Ltr capacity
and on a cool Singapore evening I used to run the engine, probably 15
- 20 minutes to get enough water to shower in.

You probably know this but it is a proper calorifier it has an over
temperature/over pressure relief valve in it. Running my 4 cylinder
Perkins engine at say 2,000 RPM for any length of time, say 45 minutes
- 1 hour, would heat the tank enough that the over heat valve would
open and flow water down into the bilge.

--

Cheers,

Bruce

I had thought of adding valves on both the flow and return, then if I ever
had a problem with the calorifier it wouldn't need to affect the engine.
I might see if I can source a 24v thermostatic valve that would shut off
supply to the calorifier once it had reached temperature.

The set up I currently have is a twin coil, 65lt calorifier with an electric
emersion heater. I have a Reflex diesel heater that runs a couple of
radiators plus the hot water. It takes a while buts works pretty well on a
cold evening, but most times through the summer it puts to much heat into
the cabin to be useful as a water heater.

Cheers
Nigel