Jaguar 28KW Combi Boiler, how to change diaphragm?

[PercyLongProng]

I have a Jaguar 28kw Combi Boiler,

Over the last week, the hot water has gradually stopped working, at first you had to turn the HW tap on full to get the boiler to fire up. This progressed until 2 taps had to be turned on full.
Now, NO hot water at all.

Central heating is fine, water still flows from HW taps but it is cold, just doesn't fire up the boiler to heat it.

Instructions say" if no hot water when taps turned on, check flow meter or that 'O' ring is not blocked.

Are these things the same as the diverter and diaphragm?

If so, how do i change the diaphragm, i've had a look and think i know where the diverter is, although this seems to have a dial on the top which adjusts pressure? it also has the safety (overflow) pipe coming out of the other side.

Am i looking in the wrong place, any idea's how i change the diaphragm if this is the problem and where i can get spare diaphragms from?

 

[ollski]

Have you got a pic of it?, can't remember if this is the rebadged glow-worm.

 

[PercyLongProng]

at work at moment...i'll try and get a pic tonight.

Where i think the diverter valve is, the mains cold feed goes into it at the bottom of the boiler, it has what looks like a large brass cap on the left, to the right is where the overflow pipe comes out, on top in the middle is a plastic cap (almost like an old shampoo bottle lid), which has pressure written on the top, coming out of the back in the middle is another pipe which looks to go into the secondary heat exchange.

My brain hurts now.

 

[boabcelt]

The dhw diaphragm is on the left hand side of the diverter valve with the dhw microswitch on the right. If memory serves correctly, the diaphragm from a vokera maxin is identical and fits perfectly. Hope this helps some. By the way,almost everything on those appliances is held togethes by o-rings and good luck!

 

[PercyLongProng]

on the instructions it says there is a microswitch about halfway up the boiler on the left. although this could i suppuse, be for the central heating.

I've created an album called Jaguar Boiler, which has images in of what i think the diverter is. it also has photo's of the boiler and display panel if that helps anyone decide if this is a rebadged model.

Will try to get pics on this message too...but if it doesn't work. please have a look at the album on my profile.

thanks.[/img]

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[petit_pablo]

The diverter is on the left hand side as you look at the boier.

To remove the diaphragm, turn off cold water to boiler and open lowest tap in house. There are two differential tubes going into the top of the valve where the diaphragm is. Remove both clips holding these tubes in and remove, they are sealed with orings. There is a grub screw or two holding the valve in place. Unwind these a bit and the brass valve will come out. Now undo the 6 screws, note which way the diaphragm is sat and replace with new. Put back together in reverse, replace the two orings if you can

 

[petit_pablo]

BTW this isnt the diverter. The two tubes in this picture go to the hw valve

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• PercyLongProng
• 27 Jun 2008
• 1

 

[nickso]

The diverter is on the left hand side as you look at the boier.

To remove the diaphragm, turn off cold water to boiler and open lowest tap in house. There are two differential tubes going into the top of the valve where the diaphragm is. Remove both clips holding these tubes in and remove, they are sealed with orings. There is a grub screw or two holding the valve in place. Unwind these a bit and the brass valve will come out. Now undo the 6 screws, note which way the diaphragm is sat and replace with new. Put back together in reverse, replace the two orings if you can

bah thats what i said before mod deleted it for some reason, maybe this should be in the combustion chamber

 

[PercyLongProng]

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.....
Can you tell this is my first posts on here.[/img]

 

[petit_pablo]

Its the most likely cause if the boiler wont do anything on hw demand.

I think the gc number of the correct diaphragm is E01217, its from a Biasi. I still have the pack from the last jaguar diaphragm i changed. E26660 for the orings too.
Parts centre (HRPC) will be able to get these parts for you http://www.partscenter.co.uk/parts/index.html

 

[PercyLongProng]

any idea how much i should be looking to pay for both the items.

I appreciate the help by the way. Thanks

 

[Agile]

The LH clip holding in the bundy tube is very difficult to refit because of the chassis member in the way even with the special tools that I have.

You will probably have to pay about £8 for the diaphragm. If you get stuck email me from profile.

I no longer have to replace the "O" rings as I know how to manage them but they are better replaced but they are rarely held in stock so may be a special order. I dont have them in stock but I will get some as I ought to keep them.

Tony

 

[nickso]

you shouldnt need to replace the rings on the venturis, i never have.

ive never had trouble with the clips either but they fit both ways so it shouldnt be a problem. i once found a jaguar with no clips holding the pipes in place, customer said no one had worked on it for 2 years

 

[PercyLongProng]

Sorted it this morning, done exactly to petit_pablos instructions.
Thanks very much for that.

Part was £11 incl. VAT. 5 minutes to open diverter up, 10 minutes to put it back together. no problem with the clips or the o rings. The tubes into the top however are a little loose even with the clips......so i took the clips off gave them a squeeze to tighten them a bit with some pliers, seems to all work fine.

I love this site and thanks for everyones replies.

 

[Lewjam]

Searched the interenet high and low for help with this one and came across this website. Had the same problem with the HW and by following the information above managed to sort out the boiler at a cost of £15 for the part. Simple job to do also total of 1/2 hour to do. Good description by this post enabled me to fix a boiler with hardly any info around. Thanks.