Vaillant ecoTEC plus 831 No Hot Water Intermittently

17 Dec 2005
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United Kingdom
Hi all
Got the above boiler, been working fine for last few years, its about 7 years old afaik.

If we get in the shower and turn it on, it works fine initially but sometimes you hear a sort of popping noise from within the bowels of the boiler (sounds like dodgy combustion) and then the hot water cuts out in the shower, but no error codes or anything on the boiler apart from the temperature indication reading on the lcd screen shows a descending value suddenly.

The only change to our boiler that we have had in the last 3-4 months is we had an additional radiator installed in a garage conversion and the plumber had to run a whole new set of pipes down to it, but this was over 3 months ago now and we have used the heating and water all the time since with no issues.
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Does the fault only occur whilst using the shower?
Does the fault only occur whilst using the shower?
yes, and I am not sure but maybe related to temperature setting on the shower as seems to have happened when we have the temperature set to very high as obviously Winter now and we have ramped up the heat, Shower isn't electric btw but direct fed.
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hmmm you have reminded me we fitted one of the restriction washers to the shower head to reduce water usage (It's one of the large shower heads) but that was probably about 8 months ago now

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