The 3 port valve has failed. Most likely it's only the actuator motor on top of the valve.
Easy job to change just the motor BUT it should be done by an engineer as this involves mains voltage connections.
Also important to get the right part as there are about 5 different valves depending on the age of your Heatslave.
bunslinger
May 2009
howtomendit.com for free repair help, information and advice.
