Vaillant Ecotec Pro 28 Noisy and Leaking

I was asked to look at a Vaillant Ecotec Pro 28 R1 (GC No. 47 044 30) by a landlord as the boiler was leaking and was really noisy when the boiler was running. There was water dripping out of the bottom of the boiler and I noticed that the pressure gauge was at it's maximum. I then noticed that the external filling loop was fully open. Surprisingly there was not water pouring out of the PRV but it was drippping. The landlord opened the tap so I could hear the noise and it sounded like the pump bearings had failed. Apparently it had been noisy for a fortnight but only started leaking that day.

The water was dripping from where the cables entered the boiler on the rear left. I could see water sintting under the pump and using a mirror could not see any other leaks. It looked as if the water was leaking from between the pump and it's housing, then running down behind the plate heat exchanger and out on the left-hand side. The new pump 178983 comes with the housing and all the required o-rings/washers. I also picked up a new PRV 178985 and Reliance Filmaster filling loop with two taps.

I replaced the filling loop to start with making sure that the non-return valve was facing the right direction. I fitted the Reliance Filmaster as it has two taps so if one gets knocked or left on accidentally the boiler won't be over-pressurised if the filling loop hasn't been disconnected as it should be when not in use.

I started to drain the boiler and also checked the pressure in the expansion vessel. There was no pressure in the expansion vessel and so I pumped it up to help with draining of the boiler. I then removed the PRV. Undoing the nut which connects to the discharge pipe is awkward with a spanner or grips, but using a tap spanner made it relatively easy. It is necessary to remove the PRV when changing the pump regardless of whether the PRV is being replaced. To remove the pump the diverter also need to be disconnected. Once the diverter is disconnected it only needs to be pulled forward before the pump can be removed once all other connections to the pump have been removed. When refitting the pump it is easiest if the tube to the expansion vessel is fitted back into the pump housing. Replacing all the washers/o-rings supplied is always a good idea as the likelihood of leaks is reduced.

Once everything was back together I refilled and heat tested the central heating and hot water. There was a lot of air in the boiler and this cleared quickest when on hot water only. Everything was working quietly and leak free.

Disclaimer: The works described in this blog are a record of work undertaken and should not be taken as guaranteed to solve your problem. Work should only be carried out by persons qualified and competent to do so.