Thought I'd share a few discoveries today. 1 - Wires on the 'Optical Sensor' are very fragile, I'm now about to try soldering a new ribbon cable. 2 - Motor run current (no load) 13-15mA 3 - Motor Stall current - 95-100mA I'll add this to my OpenTRV blog http://opentrv.homelabs.org.uk soon. Stuart