stevet wrote:
Geoff

Your right, I plan to put a pipe thermostat on the outlet pipe of the log
burner and have this switch the pump on, it'll probably need a relay near
the pump as there's about a 50 foot run to the back of the boat and at 12v
there would probably be a lot of loss unless I used thick cable. I though of
using a timer delay relay that keeps the pump running for a time after the
stat has gone open to stop the pump from cycling on and off. That should
stop any more air getting in and then once it's all bled it will hopefully
stay that way.
Remember the pipe stat will probable switch the wrong way, ie. switch
off at high temp so you'll need the relay to correct this.
I agree with Drifter, I dont think the system as descibed is ever going
to be much good, in fact it sounds a bit unsafe, rip it out and start
over. B'ain't big dollar
g