thermostatic shower - no cold - cartridge?

[gasket]

Hi folks,

I was given a fancy shower by a friend who had changed his bathroom (i.e second hand). I wouldn't normally do this but its a beautiful bit of kit (and very, very expensive new).

Spares availability from the manufacturer is very good, and my new bathroom has been fitted for it.

Hot water comes through fine, but I'm not getting any cold water through it (cold water comes from a pipe that runs into the loft and back down the bathroom wall).
When the handle is pointed to cold, the water stops.

It is one like this:

So I dismantled it and checked that the two non-return valves in the elbows were clear and working - yep.

So now I'm thinking its either the adjustment of the temperature control (manual tells you how to do this, but not sure if these can be set so hot that the cold is effectively disconnected) or the cartridge is clogged or buggered.

They are serviceable to a degree (here's a link to the instruction manual with exploded diagram). Does it sound like a cartridge issue to those more knowledgable than I?

And as a follow up - is it worth trying to clean or adjust the temperature, or should I just order a new one?

Thank you very much.

 

[DP]

I take it left is hot and right cold?

 

[picasso]

If the shower has gravity feed supplies is the shower head at least a metre below the cold supply ? if it is your problem sounds like a sticking non return valve.

 

[gasket]

Morning gents.

I take it left is hot and right cold?

Yes - thats correct. The pipework is definitely to on the left and cold on the right. The shower is also clearly marked. I'm 100% sure that the correct connections have been made.

If the shower has gravity feed supplies is the shower head at least a metre below the cold supply ? if it is your problem sounds like a sticking non return valve.

Yes it does - the hot water comes from below the bath, though there is an open head tank in the loft feeding the cylinder in the bedroom. There is just over a meter of head. The cold comes from the ground floor to the hot water cylinder, where a spur goes into the loft before coming back down the bathroom wall to the shower - again just over a meter. I thought similarly re: the non-return valves, so I've cleaned them both (see below).

So - this morning, I had another go. The checks I have done are:

1. Remove shower from wall and make absolutely certain that the pipework has been correctly connected hot and cold. Done - definitely right.
2. An idiot test: there is a hanging bracket located behind the mixer - the screw would come close to a cold water pipe buried in the wall, so I capped both pipes and turned the water on - bleeding air out at the cap to make sure I hadn't nicked the pipe. Done - definitely OK, no Black and Decker mishap there.
3. I removed both elbows (which contain non return valves) and checked them, both fine. To be certain I even cleaned them with limescale remover. Done - definitely OK.

I then did a test. I found that when I first turned the shower on (after working on the pipework), with the temperature to cold - air purged from the pipework then I got a trickle from the shower before stopping. I then turned to hot and got a steady stream of hot water for about 30 seconds, then that died too.

This leads me to one of two conclusions:

1. There is insufficient pressure from either the hot or cold. Though I think this unlikely - the shower it has replaced was a Mira Coda thermostatic bar shower, which was connected to the same pipe wrk and worked absolutely fine for years.
2. The cartridge has been fitted incorrectly (bear in mind I don't know its history), has clogged, or is in need of replacement.

Do these sound like sensible conclusions?

I would remove the cartridge for cleaning in the first instance, but I can't get the damned thing out. Need a strap spanner to unscrew the face of the mixer-body - off to Machine Mart I go.

Thank you for your help with this.