Plumbing

Moved the Caleffi 533251 3/4 pressure reducing valve (PRV) with manometer from the HW system to the incomer.

Turns out it was quite blocked. Fitted ~2012

Ordered another complete valve 533651 as  it was the same price as just the cartridge, and gave me more options if my body was damaged. Received a 2018 vintage. Thanks.

Use molegrips on the bolt head to remove it. Tricky enough in the vice. Will need to jiggle it a lot and lever it with a screwdriver. Can be removed in situ ok. Not a lot of water inside.

Tidy enough. Wiped the body out and put in the new one. A smear of silicon. A bit of chrome missing. New one isnt chromed. 

Cleaned the old one with carrefour descaler. 5 mins for the screen, and 2 x 5 mins for the body, turning it. Has dulled the brass.  In future try half strength for 5 mins.

6/8/25 noticed the pressure creeping up to around 4 bar over time and the shower dripping. Removed the cartridge and put back the original. The main seat had some scale which was removed. More chrome missing. Not convinced that it's regulating correctly. Isolated the hot water feed but that didn't change anything suggesting that it's not a mixer tap passing.