I wonder if any Forum member could help? My Vaillant ecoTec plus 831 was installed in 2010, in March it stopped giving out instant hot water when I turned on the hot water tap but heating up the radiators instead.
I employed a plumber locally who is experienced in Vaillant boiler (so he told me) and he diagnosed that the diverter valve was at fault and had a new one installed, but the instant hot water is only luke warm when the hot was turned on? Again it heated up the radiators before it gave out really hot water on tap, I asked him to come back to fix the problem, he changed the water pressure sensor and the heat exchanger but the problem is still there? Now he refused to do anymore without pay.
Currently I turn off all my radiators (luckily the weather is getting warmer) and my instant hot water gets hot a lot quicker though it still heats up the heating pipes first. Could anyone or plumber please help because my Vaillant boiler has caused me £400 of repairing fee with parts so far and yet the problem is still there?
I have to run the hot tap a little while before it reaches the correct temperatures as it heats up the heating pipe first, I waste a lot of water by waiting for the hot tap to get to the right temperature? I contacted Vaillant and they offered to repair it for a one off fee around £250, but I have already spent £400 so far.
Could it be a faulty diverter valve as it is not doing its job properly, I went to the Vailliant parts supplier and ask him whether the new part can be faulty and he did not think so?