Leaking shower mixer

tony3619

ThisIsWeird said:

Of course, to remove the whole unit from the wall, the water will need turning off! 

Plan B....the control won't come off. It must be held on by limescale or something. Im gonna call in a professional and maybe just replace the entire mixer like for like. Been trying for 2 days to remove the controller and nothing works. I might try spraying limescale remover into the internals from where the screw is for one last attempt by am getting fed up! 

GDB2222

tony3619 said:

ThisIsWeird said:

Of course, to remove the whole unit from the wall, the water will need turning off! 

Plan B....the control won't come off. It must be held on by limescale or something. Im gonna call in a professional and maybe just replace the entire mixer like for like. Been trying for 2 days to remove the controller and nothing works. I might try spraying limescale remover into the internals from where the screw is for one last attempt by am getting fed up! 

As I said ages ago, just buy a new mixer and replace it yourself. Turn the hot and cold water off, and it's a two minute job to undo the two nuts and replace it. 

ThisIsWeird

Removing the whole bar may seem more daunting, but it's actually a much easier job that removing the cartridge. It's also more of a 'known' quantity - you can pick up a complete Bristan thermo mixer bar from around £55 (there are different models, but they seem much the same?), and it is a simple case of turning off the water at the mains stopcock (assuming a combi boiler), and undoing the two securing nuts using an adjustable spanner (with jaws protected to prevent scratching). These nuts are not done up tightly, just 'nipped'; you almost certainly will be able to undo them without much effort, and the whole mixer bar will pop off.

£55-ish. That's it. Half an hour.

How much might this cost to have a plumber out, especially when they won't know if it's fixable until they see it? If you do go for this option, then perhaps also consider a whole new bar rather than a replacement cartridge?

tony3619

ThisIsWeird said:

Removing the whole bar may seem more daunting, but it's actually a much easier job that removing the cartridge. It's also more of a 'known' quantity - you can pick up a complete Bristan thermo mixer bar from around £55 (there are different models, but they seem much the same?), and it is a simple case of turning off the water at the mains stopcock (assuming a combi boiler), and undoing the two securing nuts using an adjustable spanner (with jaws protected to prevent scratching). These nuts are not done up tightly, just 'nipped'; you almost certainly will be able to undo them without much effort, and the whole mixer bar will pop off.

£55-ish. That's it. Half an hour.

How much might this cost to have a plumber out, especially when they won't know if it's fixable until they see it? If you do go for this option, then perhaps also consider a whole new bar rather than a replacement cartridge?

A quick update on this....so the mixer suddenly stopped leaking so I didn't bother sorting it yet. But Ive just discovered that the reason it stopped leaking was because the lower the temp on the control the less it leaks. If you turn the dial all the way to 15c it stops completely. If you turn it to 38c it will leak quicker than at 34c...

So now I definitely will be replacing it but any clues why it would do this? 

ThisIsWeird

tony3619 said:

A quick update on this....so the mixer suddenly stopped leaking so I didn't bother sorting it yet. But Ive just discovered that the reason it stopped leaking was because the lower the temp on the control the less it leaks. If you turn the dial all the way to 15c it stops completely. If you turn it to 38c it will leak quicker than at 34c...

So now I definitely will be replacing it but any clues why it would do this? 

Thanks for the update.

Is it being supplied by a combi boiler? If so, then both the Hot and Cold will be at the same pressure - so it can't be that!

Counter-intuitively, a worn ceramic disc cartridge can drip if it's at too low a water pressure as the discs aren't being pressed so firmly together, but that wouldn't appear to be the case here. The thermostatic cartridge will have separate H&C inlets, so I guess the leak must largely be coming from the H side? Or, perhaps the rubber seal wot's letting the drips out is more worn on one edge, and the temp adjusting spindle is fractionally off-centre so presses against this wear - thereby stopping the drip - when in the cold position?

No idea. There is no obvious cause I can think of.

Of course, once the hot weather is over, you'll be dripping again... :-)

tony3619

ThisIsWeird said:

tony3619 said:

A quick update on this....so the mixer suddenly stopped leaking so I didn't bother sorting it yet. But Ive just discovered that the reason it stopped leaking was because the lower the temp on the control the less it leaks. If you turn the dial all the way to 15c it stops completely. If you turn it to 38c it will leak quicker than at 34c...

So now I definitely will be replacing it but any clues why it would do this? 

Thanks for the update.

Is it being supplied by a combi boiler? If so, then both the Hot and Cold will be at the same pressure - so it can't be that!

Counter-intuitively, a worn ceramic disc cartridge can drip if it's at too low a water pressure as the discs aren't being pressed so firmly together, but that wouldn't appear to be the case here. The thermostatic cartridge will have separate H&C inlets, so I guess the leak must largely be coming from the H side? Or, perhaps the rubber seal wot's letting the drips out is more worn on one edge, and the temp adjusting spindle is fractionally off-centre so presses against this wear - thereby stopping the drip - when in the cold position?

No idea. There is no obvious cause I can think of.

Of course, once the hot weather is over, you'll be dripping again... :-)

I do think you may be right about the rubber seal beings worm in one area because when the dial is turned to different temps the leak appears on different parts of the dial such as at 38c the water drips from the top and on 34 it drips out the bottom. 

My first theory was that turning the dial to lowest possible temp of 15c is clockwise so  it count be tightening the cartridge up just enough to stop the drip...

ThisIsWeird

Possibly - I'm not sure what happens inside the cartridge when the temp spindle is turned. Is it a screw thread, so the internals are moved in and out, or does it tension the wax cartridge, or what.

Anyhoo, one day you'll have to replace it

Strongly suggest you go for a full unit replacement - two large nuts. Easy peasy.

Meanwhile, keep an eye on t'Bay for new showers on auction and good chance you'll pick one up cheap 

tony3619

ThisIsWeird said:

Possibly - I'm not sure what happens inside the cartridge when the temp spindle is turned. Is it a screw thread, so the internals are moved in and out, or does it tension the wax cartridge, or what.

Anyhoo, one day you'll have to replace it

Strongly suggest you go for a full unit replacement - two large nuts. Easy peasy.

Meanwhile, keep an eye on t'Bay for new showers on auction and good chance you'll pick one up cheap 

So I am finally looking to swap the entire mixer but notice some models say "fast fit connection" or "adjustable centres" while others don't. 

I'm aiming to keep the existing wall mount and face plate and literally just swap over the mixer but don't know if all mixers are universal nuts? I was going to go with the same manufacturer with the the same 150mm centres between hot /water feed and hope the nuts screw to the wall mount?