Also No Domestic Hot water

Same problem as you Ian , Question is, Do we really nead this blender valve ?, would remove and replace with straight couplings, then use cylinder or boiler thermostats like most heating systems, solve this problem from happening again ?. I'm Really not sure thats why I'm asking.

Hi, See Mikes descrition of how this system is different from a standard system, -BE CARFUL with hot water. - see his notes on common problems with boilermate 11, 1)Check it's full up, 2) is pump running ok, 3)Is blending valve scaled up/faulty. Never replace a blending valve with anything esle, it protects the user from scolding water at the taps. This is because the thermal store temperature should be 75degC to transfer enough energy into the mains cold water as it flows to the hot taps, not the usual 60degC on a vented boiler/cylinder system. Try reducing the flow rate for a higher temp, if this works, discale the heat exchanger or live with it or replace system. Good luck Paul.

Thanks for your help paul, I've eventually found an Exellent Heating Engineer, As in one that will do repairs to Gledhill Boilermates in Glasgow.

He Replaced the Brawa mixer Valve for me next day. Sorted.

Cheers.

Musky.