Valliant old combi bolier, we had just a leak repaired and the system was drained down.
now the hot water fluctuate from hot to cold and there is no central heating. Bolier makes strange noise (pump?) that did not do before.
any idea?
now the hot water fluctuate from hot to cold and there is no central heating. Bolier makes strange noise (pump?) that did not do before.
any idea?