I have a circulating pump that is attached to a back boilder in my fireplace.
I would like to add a thermostat so I do not manually have to turn on/off the pump i.e it senses when the water is getting warm when I light the fire and automatically switches on/off the pump.
Its a standard grundfos domestic pump.
Buy a pipe thermostat from any plumbing suppliers, check with continuity meter and wire to circulating pump. Make sure you fit the pipe stat on the flow pipe from the back boiler as close to the back boiler as possible.