Shower/bath mixer tap broken

6 Oct 2016
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United Kingdom
Hey guys,

I was hoping for your advice as I have little experience of plumbing and want to have a bash at fixing this myself.

Long story short, the bath tap/shower seems to only be able to run from very warm (at coldest) to quite hot (at it's hottest). So it doesn't go hot enough for a hot bath, or cold enough for a cold shower. It used to be able to do both of these since I had a new boiler fitted a couple of years ago. Water in the other bathroom's shower runs normally - very hot and pure cold.

Please see the attached photo - the brand is Grohe - and it was originally installed c. 2003. Does anyone know if the thermostat is contained within the tap itself, or whether it'll be behind the tiles somewhere? And how likely is it I could fix the problem myself?

Thanks in advance for your advice - much appreciated!



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It will be within the tap, on the right hand side.

a) Isolate hot and cold supplies.
b) Remove right hand handle (probably a 2mm or 2.5mm allen grub screw behind handle).
c) Remove and replace cartridge.
d) Reassemble.
e) Turn hot and cold on again.

To isolate hot and cold supplies:

1. If isolation valves fitted to shower hot and cold supplies, simply turn off. (Might be under bath panel)

2. If no isolation valves, then:
2a. If a combi boiler, turn off boiler, turn off water at main stop cock.
2b. If non-combi (separate hot water cylinder) then
i) turn off cold feed from cold cistern (in loft?) to hot water cylinder. Probably gate valve in airing cupboard on a down pipe from loft
ii) turn off cold supply to taps. Again probably a gate valve in airing cupboard, on down pipe from loft
2c. Make sure hot and cold are off before proceeding
Thanks so much oldbuffer - I'm going to take a look on Friday and will report back!

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