Worcester 28cdi diverter valve

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Hi all,I’m hoping someone can help me out, I’m about to replace the diaphragm on the diverter valve and replace the heat exchanger, but a lot of people say don’t touch the isolation valve on the C/H flow and return as they are prone to leak after, need some advice on what to turn off to do this job, should I turn the mains cold water off and maybe close all radiator valves upstairs (as my boiler is on the ground floor)
Any help or photos would be much appreciated thanks, yes I know this is a very old boiler but I stuck for cash and this seems to be my only way.

Read more: https://www.diynot.com/diy/threads/...n-worcester-24cdi.433196/page-2#ixzz7HkKrzYcb
 
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Good luck,correct don’t touch the valves they will leak,you need to isolate and drain the cold water and heating.turn off electric to boiler and cover the control box containing the pcb as water will spill out.have some towels handy as it’s a difficult job .
 
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Good luck,correct don’t touch the valves they will leak,you need to isolate and drain the cold water and heating.turn off electric to boiler and cover the control box containing the pcb as water will spill out.have some towels handy as it’s a difficult job .
Thanks, so I can isolate the cold water from the mains, but to drain any existing water in the boiler do I undo the white drain plug on the L/H by the heat exchanger, as for the C/H if I turn all the rads off upstairs the only water left in the system will be from the pipe runs and what’s left in the boiler, Am I doing this correct, as for the electric’s yes they will be isolated and any wiring disconnected and covered up (front control panel removed as well)
 
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no need to close any radiators, isolate cold water inlet an leave boiler drain points open as you work, basin and loads of towels
 

MJN

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Many years ago I uploaded a bunch of photos capturing my repair of a 24CDi and it may be worth having a look/read through if you haven't seen it already:

https://www.newtonnet.co.uk/house/boiler/
(Apologies for the inline adverts - I used some code that allowed Google to insert them where they wished and didn't realise how intrusive they can be. Will have to take a look at that... although they do make a fair bit of money for something that just sits there!)

Whilst not intended as a guide per se (I am not experienced enough to speak authoritatively on the subject) it might give an insight as to various aspects of what's involved. All that said, to do this day I continue to receive emails from people who have successfully completed the repair guided by nothing but the run through - whilst weeks and months can go by these days without hearing anything I must've received many many hundreds (easily >500) over the years (17 years looking at the timestamps!). For some it goes without issue, for others they have all sorts of issues that wouldn't be out of place in a Laurel & Hardy film.... In all cases though they've eventually got there, and I recall vividly one particularly touching email from a wheelchair-bound chap who was waiting days over Christmas for British Gas to come out to repair his boiler (none of his local 1-man bands were interested) and, at his wits end and the cold really starting to affect his physical and mental health, tackled the job using his wife as the tool-wielding proxy who apparently barely knew one end of a screwdriver from another. Together they managed the job, and whilst it took them all day I can only imagine the feeling of pride and relief when they finally got their heating and hot water back on. Whilst I can't speak for their Christmas, I know it certainly made mine!
 
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I replaced those dodgy isolation valves with some standard ones from Screwfix a few years ago.
 
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If you are doing the diaphragm with the diverter valve in situ, something similar to these will be handy for the screws at the rear of the valve top.
3 Pc Offset Screwdriver Set Double Sided Cranked Right Angle Bent - 54069C 5038673540696 | eBay
Also, as these boilers are notorious for being partly made of razor blades, some of these may be of use
LATEX FREE PLASTERS Sensitive Skin Strong Stick Wound Cut Graze Bandage Cover | eBay
Yes thanks for that, I have one of those
 
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Many years ago I uploaded a bunch of photos capturing my repair of a 24CDi and it may be worth having a look/read through if you haven't seen it already:

https://www.newtonnet.co.uk/house/boiler/
(Apologies for the inline adverts - I used some code that allowed Google to insert them where they wished and didn't realise how intrusive they can be. Will have to take a look at that... although they do make a fair bit of money for something that just sits there!)

Whilst not intended as a guide per se (I am not experienced enough to speak authoritatively on the subject) it might give an insight as to various aspects of what's involved. All that said, to do this day I continue to receive emails from people who have successfully completed the repair guided by nothing but the run through - whilst weeks and months can go by these days without hearing anything I must've received many many hundreds (easily >500) over the years (17 years looking at the timestamps!). For some it goes without issue, for others they have all sorts of issues that wouldn't be out of place in a Laurel & Hardy film.... In all cases though they've eventually got there, and I recall vividly one particularly touching email from a wheelchair-bound chap who was waiting days over Christmas for British Gas to come out to repair his boiler (none of his local 1-man bands were interested) and, at his wits end and the cold really starting to affect his physical and mental health, tackled the job using his wife as the tool-wielding proxy who apparently barely knew one end of a screwdriver from another. Together they managed the job, and whilst it took them all day I can only imagine the feeling of pride and relief when they finally got their heating and hot water back on. Whilst I can't speak for their Christmas, I know it certainly made mine!
Yes I had a good read through your post on this, very good but I noticed you isolated the CH flow and return from underneath the boiler, this is what I didn’t want to do just in case they don’t reseal, another person has told me to just isolate the cold water supply and drain using the two white drain offs underneath the boiler
 
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It's pure luck with the flow/return isolators but not touching them is always the best course.
The PITA is that you've got everything back in place and then they leak. Some will try heating the spindle up to cook the O ring, I've even had Worcesters own engs. whack 'em with a hammer.
To replace the valves means the whole bottom end has to come out again (inc. gas valve connections so a reg. installer req.) and then the securing plates...the valves pull out through the backplate.
 

MJN

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Yes I had a good read through your post on this, very good but I noticed you isolated the CH flow and return from underneath the boiler, this is what I didn’t want to do just in case they don’t reseal, another person has told me to just isolate the cold water supply and drain using the two white drain offs underneath the boiler

Yeah, sounds sensible. I only ever did the job a couple of times (different boilers) and didn't have an issue but it sounds from those with more experience that they can present a problem and so best err on the side of caution and leave them well alone!
 
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