Cold water tap starting boiler

perc

Hello

I have noticed over the last few days that the cold tap in my upstairs bathroom has started to engage the Valiant combi boiler.

When the cold tap is turned off the boiler comes on as though it is starting to produce hot water for a split second before stopping. It is only the one upstairs cold tap that does this and all other functions are fine.

Does anyone have any ideas what could be causing this at all?

[Deleted User]

Mine did that for a few weeks after it was first installed, I think it was because the plumber left a dead length of pipe with an airlock on the cold inlet.

EssexExile

Do you have any taps that you rarely use? Run them for a bit, if they splutter there was air in the system as mentioned above.

bris

Is it a single tap that does both hot and cold? The cartridge may be faulty and passing hot water. Flow switch may also be the culprit.


You could take the bath panel off and check for dead legs under or near the bath. This often happens with all taps but maybe if it's close enough to the bath tap it could make sense.

jessmist

Hi,
i had a new Valiant combi boiler fitted. And after a few days I noticed that turning on my cold tap on it made the boiler fire up.
I had mine installed by BG so called them out to check what was wrong.
Turns out it was to do with a setting in the boiler that needed changed as it was too sensitive.
The engineer had to call Valiant technical so that they could talk them through changing the setting.

Hope this helps.