I must have missed where he indicated there was a hot water valve thermostatic regulator.
If the intent is to prevent boiling and/or excessive pump noise/speed then when the thermostat indicates off, the excess water heat must be dumped to prevent boiling with a recirc. valve and/or flame controlled .
so it is not clear to me how heat, pump, air temp and flame are controlled.
Normally design specs would indicate setpoints for safety and comfort with upper/lower values for water, pump and air temp. with sensor fault detection.
I'm not even thinking about room temperature. The boat you see in the top left hand corner of this post really is our home - myself and Kath;s (Gord bless her) - and has been for the last 15 years. We love our life aboard but the control aspect that you would associate with household heating goes out of the window. Our boat is 30' x 9'6" and seperating us from an English winter is 3/4" of mahogany. We've had (in 2010) temps down to -17C, very unusual but does happen here from time to time.
Our aim is to redistribute the heat from our solid fuel stove, from the salon to both the bow, where we sleep and the stern where we need to keep the electronics in our washer /dryer above freezing. We can control 'room temperature' with the rotating air wheel on the front of the stove. If we do get another hard winter we'll top up the heating shortfall with marine electricity.
The main point of this experiment is for the PWM to adjust the circulating pump's RPM to a minimum to do the job, without allowing the system to boil and do it at the fewest decibles possible. The only possible place onboard, for the pump, is directly below our bed and the pump noise, at 14 litres a minute (flat out) would be intrusive, If the fire goes out - the pump should stop.
Thoughts? (no, getting a house will never happen!!!)
Thanks to all, Stu
Edited twice to add
Thanks Chris, apart from the room stat you were the closest I think.
To avoid any possible confusion, at best we can rely on between 5 and 6kws from the stove anything more would come from electricity.