The receiver gets the signal from the thermostat ok, as it flashes ¾ times when receiving the signal (approx. every 3 mins).
The boiler switches on/off ok at the desired times so the transmission is ok.
The boiler will frequently accelerate past the desired target temp. If I manually move the target much below its current temp, the boiler gets the message and stops heating. But the next time I use the heating, the boiler just warms the water so the rads only get warm (not hot), even though the target temp is much higher than current temp. By playing around with the thermostat, moving it to manual & back to schedule, back to manual eventually the boiler starts heating but there doesn't seem to be a set procedure to kick the boiler into FULL heat mode. The boiler just seems to be just heating the rad water to about 35 deg. I'm assuming the WR1 thinks that it has almost reached the target temp, and has reduced the heat to the water to ease up to the target temp rather than accelerate past it. But the target temp is far higher than the current temp
The thermostat is not the current on sale model (it's a British Gas and I think it's a rebadged Drayton Digistat SCR).
Before you ask, have I tried resetting it, changing the batteries, Yes I have tried re-pairing the receiver to the digistat many times (which does sort the problem but only for that occasion) and the problem reappears next time I use it.
Would appreciate your support please.