Mira Excel leak after changing cartridge


2 Jul 2006
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United Kingdom
I had a drip from our Mira Excel showerhead and, on the advice of several web searches, I replaced the cartridge - 903.33

I discovered after removing the old cartridge that the hot water will not shut off completely - looks like the valve doesn't completely close, no matter how much I try to turn it.

This means there was a constant trickle of hot water still coming through the pipe when fitting the new cartridge and it was not able to dry out before fitting the cartridge.

Could this be a reason for a leak from around the bottom of the cartridge ? I've tried loosening and tightening the screws to varying degrees but it makes no difference. Also, the leaflet with the new cartridge mentions a Guide P2998 but I can't find this anywhere - is this downloadable anywhere ?

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Fitting it "wet" is not a problem. Are you sure there is not an O ring missing? I changed one of these and dropped an O ring without realising it - it leaked!
Thanks for your response.

The leak might have stopped for now - I'll wait and see if it lasts !!

Problem I have now, though, is a bit of a lack of water pressure, especially on the cold side. When turning the temperature control in either direction the pressure seems to drop completely then come back on. If I turn the temp down to 1 or 2 there's hardly any pressure at all. Fully up to 9 or 10 and it's OK(ish) but just a bit hot !!

I adjusted the setting to low pressure as this was how the old one was set. The cold water comes from the tank in the attic and, yes, it's switched on again.

Any thoughts ? I don't know if there are any other adjustments I don't know about, not having a proper installation guide. Is it something I've done/not done or could the cartridge be faulty ?

You have an air lock in cold feed from tank, take off shower head, let the hose hang down in shower tray, turn on shower valve fully in hot position to establish good flow of water then turn temp setting quickly to cold and run for a minute or 2. This will pull cold water down feed pipe and remove airlock. Happy days ;)
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