Central Heating won't heat radiaters but do have hot tap water?

I have an Optima 700 boiler/central heating system. When I turn up the room thermostat it clicks but the boiler doesn't heat the radiaters. Pressure is above 1 bar. I do get hot tap water just no heat to the radiaters. Any suggestions?
Bob, March 2006


done
it could be a diverter valv problem when the boiler is cold just demand ch if is diverter valv problem the boiler will come on reach the max tem within the boiler then go of

ziggy, March 2006
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