if it is only doing it first thing on the morning, or some reson the pump is not switching on, check 3 way valve, air looks , is there enough water in the header tank?
erj, September 2010
thermostat could be gone in the hot waterboiler causing it to keep heating the water when its alredy boiling then heating the water in the pipes all the way up to the cold water tank, thermostat should be replaced if this is the case
