No CH but HW is fine - pump issue or sensor issue?

Just wondering if someone can provide some initial guidance before i have to call someone in for what may be a simple fix (I have no real experience in this area I'm afraid)

Having turned up the room thermostat and ensured the heating is switched to constant on the boilermate, no radiators are getting any heat. I've had a look inside the boilermate and checked on the installation guide to interpret what the LED display is telling me. It shows that:
H1.1 - Middle store sensor calling for heat
V1.1 - HW Programmer calling for heat
V1.3 - CH Programmer calling for heat
V1.4 - Room thermostat calling for heat
V2.1 - Boiler on
H2.2 - CH Pump on
H2.3 - Boiler system pump on

It does NOT show the H1.2 - Bottom store sensor calling for heat.

I've checked for fault codes and each slot just shows FF. The sensor readings (and control points from the guide in brackets) show:
S1 - Middle store sensor on - 74 (68)
S2 - Middle store sensor off - 75 (77)
S3 - DHW in - 52 (35)
S4 - DHW out - 63 (55)
S5 - Bottom store sensor on - 74 (60)
S6 - Bottom store sensor off - 74 (70)
Thete is an S7 reading of 86 for which there is no reference in the guide.

Despite no immediate response when attempting to turn the heating on, the CH pump does makes a slight rattling sound a couple of minutes after turning the heating "on".

Sorry to throw a lot of information but any guidance would be greatly appreciated. Is it the sensors, the pump or possibly something else completely? Hopefully something i cam fix myself.

Is the pipe coming out of the ch pump hot?

Could be a pump issue, are any radiators getting hot at all?

First thought is it sounds like a pump issue. Try wiring the CH pump to a live and a neutral from the mains... If that doesn't make the radiators warm up then you have a pump issue. If it does make them warm up it could be a board issue but that seems unlikely.