motorised valve powered closed

[james_r_warner]

I am looking for a motorised valve which can be powered closed but will open automatically based on high temperature to a pipe stat or if the power fails. Any ideas

 

[gassafe]

Is this for a solar circuit? Or what usage?

i know there available, but not fitted commonly!

 

[snowhead]

Very common.
Used on solid fuel systems.

HONEYWELL V4043B1257 NORMALLY OPEN 2 PORT VALVE NEW | eBay

 

[james_r_warner]

Is this for a solar circuit? Or what usage?

i know there available, but not fitted commonly!

thanks gassafe

The log burner has a water heater. We are pumping the hot water from the water heater to a heat store. However if the power fails when the log burner is running the pump would stop and there is a risk that the water heater would overheat. We have therefore fitted a gravity circuit to a 1KW radiator which we only want to open in the event of a power failure or of over heatig in the flow from the water heater. Hence the need for the motorised valve to be powered closed but open in the event of a power failure or high temperature (>90C) to the pipe stat on the flow pipe.