Sludge build-up

Another interesting job to start the year. I was called to a client on the Bitterne/Sholing border in Southampton who had no central heating or hot water. The boiler was firing but only for short amounts of time – maybe 1 or 2 minutes. The boiler was operating fine, the timer and room thermostat were asking for heat ok. The causes for this fault were narrowing down to be either the circulating pump or a dreaded blockage. Having tested the pump was live and running it was conclusive that the system was literally blocked.

One look at the feed and expansion tank in the clients loft and it was easily identifiable as a sludge ridden system. I cleared the sludge in the tank (‘sludge’ is the generic term for ‘iron-oxide’ – a metallic ferrous build up of broken down radiator matter within the system. The mixture of oxygen and hydrogen in the water passing through steel radiators is a reciepe for rust – and that is exactly what had caused this blockage in this system). I began to attach hoses on all of the drain-off points (in order to empty then system fully). With my experience I knew where the blocked pipe usually is on this type of system and continued to clear out the solid build up of rust/sludge.

The only way to stop, prevent or reduce this happening in the future is to frequently (every 4 to 7 years) have your system flushed, then drained completely and finally refilled with a good quality Corrosion Inhibitor (which inhibits rust and sludge within the system). The process is relatively simple. It doesn’t take any more than 2 hours and the rewards are a clean system with clear water passing through the boiler, the radiators and the hot water cylinder – which in turn reduces wear and gives greater heat output from the gas being burned. This could also reduce gas consumption, as the boiler is heating fresh water and not sludge.




No comments yet