Should the blender be all the way open?? I did notice a few days ago in the night I kept hearing the motorised valve operating often, I've just manually set to open to see If that cures it?
Don't muck about with the blender valve to the point it over heats your floor. I believe the absolute top limit is 55C (and your boiler will be outputting 70-80, hence need for the blend). Thing is, if your manifold is getting hot, there must be some flow through it (therefore the zone valve open) - perhaps only one of the loops though. Set all the thermostats to cold, let it all cool. Then set one on (and make sure none of the others do) to max for 30 mins and see if the manifold gets hot. Knock it off, let it cool, try again. By doing this, you'll find if at least one of the loops are working.
Does your manifold have any individual flow meters on the flow or return - and is the water black or clear?
I'm not familiar with the polypipe UFH controller... Should all the LEDs be green, like the power one or should they be red (as they are) when correctly operating?
Have you tried the first rule of troubshooting... Power off/power on?
Also check the pins aren't stuck under the actuators.
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