Thermostatic Mixer Shower

[matt4444]

Hello all

Our thermostatic mixer shower above the bath has given up the ghost after 10 years (think it's the cartridge). It doesn't owe us anything and is looking a bit worn anyway so I've bought a replacement shower as a straight swap. I've taken the bath panel off and there is an isolation valve to the shower cold feed and to the cold and hot bath taps but not to the shower hot feed. There is a wider connector of some sort but no valve on it - not sure what that is. See photo. As you can probably tell I'm not very clued up on this. I assisted my late Dad when he fitted the bathroom for us but that was 10 years ago and I'm not sure why there is no isolation valve on the hot shower feed. We have a combi boiler. Do I need to turn the mains water off to swap the shower over. Am I missing something obvious here?

Thanks in advance

Matt

 

[terryplumb]

pics not very clear ,however if you have a combi boiler ,and no hot water cylinder ,or loft tanks, you turn off your boiler ( isolate electric supply to it ), close down your mains cold water stopcock ,then open up hot and cold taps upstairs and downstairs .this will drain out the pipework and allow you to work on mixer.....tip ....before turning off water fill kettle !!

 

[matt4444]

Thanks Terry. Sorry I should have described the photo. The nearest pipe is the cold with the tee going up (with isolation valve) to the cold bath tap and into the wall for the shower (this also has an isolation valve). The furthest pipe is the hot and this also has an isolation valve on the tee for the hot bath tap but no isolation valve going into the wall for the shower. I was hoping for a quick fix expecting to turn off both isolation valves to the shower (the rest of the household would be none the wiser whilst it was going on) and swap the shower over. What I can't understand is why my Dad didn't put one on the hot pipe for the shower and of course he is no longer around to ask.

 

[terryplumb]

there is a brass fitting that is obscured in your pic ,on the hot supply to shower , it may be a non return valve .you can usually isolate the hot at your combi boiler ,isolate cold to shower as you intended ,and leave the mains cold stopcock on. that will give the rest of the house cold water at least.

 

[matt4444]

Thanks again Terry. I wondered what that fitting was but that must be it - a non return valve. So I'll isolate the hot at the combi and as you say the rest of the household can still fill the kettle and flush the toilet!

 

[dpsservices]

I’d also change the isolator on the cold feed to the shower to a full bore lever isolator myself and also add one to hot supply to shower
Regards david