Honeywell Radiator Thermostat Boiler Working But Radiators Aren't Getting Warm. Any Ideas? System Has A Worcester 40CDi And 2 Zones.?

Boiler working but radiators aren't getting warm. Any ideas? System has a Worcester 40CDi and 2 zones.? - honeywell radiator thermostat

I 40a Worcester CDi boiler combine two areas, one of which is an area under-floor heating and the other is the rest of the radiator. Each zone has a separate cable drive thermostat. The radiators are at best lukewarm, and bleeding in the Arctic. The two values of the area, I think they are Honeywell, are in different positions? Is that what determines the radiator to heat? Any help would be very welcome as a plumber my vacation!