Brentford Combi Boiler pump repair on a Vaillant Ecotec 831
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If you do find any unusual noises coming from your boiler don’t ignore them as when winter comes the strain on your boiler will double what is in summer.
On this Vaillant Ecotec 831 in Brentford the circulating pump was on its way out and the noise was getting louder.
The operation involved isolating the boiler from the central heating system and electricity. No need to drain down the whole system, just the boiler.
At this stage we can also check that there is enough pressure in the expansion vessel. On this occasion there wasn’t any. This causes the central heating system not to work correctly. So by adding the correct amount of air we also get any excess water out.
Now that the boiler has no water in it, we can remove the original Vaillant head only. On this boiler repair I bought a Wilo replacement pump head only as the back was in good condition. This makes it an easier job and more cost effective.
Once the new Wilo pump head had been bolted in and connected to the ECB. I opened up the Flow and Returns for the central heating system and replenished the boiler water via the filling loop, adding a top up of inhibiter.
After firing up the Vaillant Ecotec 831 I checked the pump operation and central heating system for excess air…. PASS!
I did notice though the water from the boiler was quite dark and the last radiator wasn’t heating so well. So I will suggest a Magnaclean filter and a Powerflush. 
