Build up of sludge rust /blockages
The Reported Problem
The customer reports a dripping from the boiler’s safety discharge pipe and a very high pressure reading on it’s gauge. In this case, a ‘Sealed System’ requires the manual injection of mains water into the central heating to pressurise the system via a ‘Filling Loop’.
The original fault here was the customer not fully making sure this filling loop was properly shut off. This sadly meant there had been a constant, slow introduction of fresh water being introduced into system, producing rusty water and in turn sludgy deposits. This excess water had – Over time – been passing through the high pressure discharge valve known as a PRV; as seen in the picture a build up of deposits which had backed up to the boiler. With all sealed systems there must be an expansion vessel to safely absorb the expanding water volume. Again, the blockage had found its way leading to this vessel, creating more problems.
The expansion vessel and it’s pipes were cleared, the gummed up PRV was replaced and a new ‘Double isolation’ filling loop was installed to help prevent this kind of fault reoccurring.