Jaguar 28KW Combi Boiler, how to change diaphragm?

[SLaw33]

Thanks for that petit_pablo,

More questions now thoug....typical.

With the instructions saying, check the flow valve or that the 'O' ring isn't blocked.

Do you think the diaphragm is the most likely cause of the loss of hot water.

It looks like the flow valve is around where the first photo's i took are.

With the diaphragm, is it something a non plumber would have a problem doing...i've done a bit but not loads.

Also, any idea where i could get new o rings or the diaphragm from...or one that would fit at least since Jaguar have dropped off the face of the earth, thanks to hepworth i think.

i've included more photo's of the thing i think i should be dismantling now.

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If you click on the photo's i think they enlarge.....
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Here is a picture of a dismantled Jaguar diverter valve showing the badly disintegrated black rubber diaphragm compared with the new one next to it. The part number of this 78mm diameter diaphragm is:-
BIASI DIVERTER VALVE Diaphragm BI1011102

Cost is about £3.50 on ebay inc p&p.

Untitled

• SLaw33
• 26 Jan 2014
• 1

 

[Mintnick]

love this site - thanks in advance for all the tips and instructions people!

As everyone has already mentioned i am currently suffering the same symptoms ! run hot tap on max and the shower will respond to giving me hot water not cold! been like this for months. Initially i thought it was previous problem, the gas valve (gas engineer needed to get involved - respect the gas all that) , but no error message this time, so i thought lets go to DIY NOT and this site is just mint! got the answer i needed, and like the PCB i had to replace many moons ago, this one is a job for the me - a DIYer!

so just to confirm :-

Part: O RINGS - *********HOW MANY DO I NEED?***********
Part No: 0020027585
Stockist : Part Center .co. uk
Current Price: (September 2014) £10.43 inc VAT

Part: 78mm diameter diaphragm - BIASI diverter valve
Part No: bi1011102
Stockist: (various) Part Center .co. uk
Current Price: (September 2014) £15.70 inc VAT

Thanks in advance

 

[Mintnick]

Yes I can confirm the part that needed replacing was truly well split in many places, the rubber disc shape part is like most things, with wear and tear playing apart eventually!

More or less easy to replace, although my experience was some what difficult with getting the chrome coloured pipes off the diaphragm. In the end it was easier to disconnect the pipes where they are connected into another part on the boiler on the right hand side. It was then easier to remove the pipe from the diaphragm once out of the boiler. And I also replaced In the end replaced in total 4x o rings.as the silver chrome coloured pipes have o rings at each end. And once the new rubber diaphragm is replaced it was also easier to reconnected pipes with sir clip/pins outside of the boiler. And then weave the diaphragm and pipes back in to the boiler and reconnect the pipes on to the part on the right hand side of the boiler for the reversal of the fit.

Once all fitted works like a dream. Shower works without having to run the bath got tap in full.

Top tip, the reason I had issues with these chrome pipes that go into the diaphragm was purely down to limescale build up this makes sense with living in a hard water area. The limescale prevents easy removal. So I managed to scrape some of the lime scale off making easier refit possible. So if you have issues getting these pipes off, be brave and pull/push a little harder than you may think might be right, as I initially thought, as the pipes are easily bendable.

Summary the whole task is not that scary.

You can get a diverter kit from eBay and such alike, for around 35.00 which I think comes with a better rubber diaphragm.

 

[Mintnick]

The part on the right I am referring to, where the two silver pipes go into from the diaphragm (also known as the differential valve) is called the water flow sensor (brass in colour) and yes there is a retaining screwed and small angled bracket that's needs to be removed.