Bristan CART5 thermo. mixer cartridges – repair possible?

[ChrisOxford]

I have a Bristan “Jive” thermostatic mixer shower bought about 5 years ago and fed from my Worcester 280RSF combi. I bought it end-of-line in one of the DIY sheds for about £50, allegedly reduced from about three times that figure.

It was very easy to install and worked perfectly for a year or so, then water suddenly started seeping out between the body and control knobs, so I replaced the 3 seals (a fiver or so from National Shower Spares) and things were fine again.

But after another year, the maximum temperature began to decrease and before I knew it, I was having to have lukewarm showers. The non-return valves and filters were clear. I happened to have a spare unit (who wouldn’t buy two at that price?!) and swapping the cartridge got things back to normal.

But now the same thing’s happened and new cartridges seem to be the best part of £100 which seems a lot for something that lasts just a couple of years. So, is there any way I can repair the old cartridges? If I do manage to take them apart, what’s likely to be the problem? Water is hard round here, but the cartridges don’t seem visibly scaley.

This is what the cartridge (CART5, 067320) looks like:
http://img.showerdoc.com/images/products/BRIST-06732COMPL.jpg

Thanks

 

[Youllneverguess]

Buy a new shower. Or cartridge.

You might try soaking in warm vinegar, nut I'd say its goosed.

 

[ChrisOxford]

Thanks. So that's probably a "No" then

Anyone else had any experience with the cartridges? Do they usually only last a couple of years?

 

[denso13]

We did have a problem with Mira cartridges only lasting 12-18 months on new builds. Turned out water pressure was too high (think mira is 3 or 5 bar max). Started to fit pressure reducing valves on every install and problem went away.

 

[ChrisOxford]

Ah! Thanks for replying.

Going to dig out my pressure tester and read the MIs again

I've got nothing against forking out for a new cartridge if it's likely to last a reasonable period, but £50 /year running costs seems excessive to me! I know Bristan aren't up there with Mira in terms of quality, but they're hardly cheap c*&p either.

C.

P.S. As the gauge has got a 3/4" BSP connector on it, it will be easy to connect to the WM outlet in the kitchen, directly below the shower by about 8 feet. Presumably that would give me a close-enough figure for this? Or should I try to make up an adaptor with one of those garden hose adaptors that attaches to a tap with a jubilee clip and use the basin in the bathroom?