Vokera Maxin 24e - No Hot Water - suspected diaphragm

[thetopcat84]

Hi guys,

As the title of the post suggests, we're having boiler problems at the moment.

It's a Vokera Maxin 24e and until recently was fine, but suddenly the domestic hot water (dhw) stopped working. I've had a bit of a google and from what I understand, the diaphragm is a regular culprit for this sort of thing.

So, the diagnosis... whenever we have hot water taps running, we can hear running water going through the boiler (can feel the cold water running to the distribution manifold). However, there's no fan or ignition.

I took off the cover to the micro-switch and when the arm's pressed, the fan and ignition fire up.

So that's why I think it's the diaphragm, but this definitely isn't my area of expertise, so was hoping someone could confirm or correct me on this?

Thanks in advance.

TC

 

[thetopcat84]

Seem to be getting a lot of views, but no replies....

I've taken the plunge and ordered a new diaphragm, hopefully it'll be ok and I'll post results in case anyone else finds it useful....

 

[45yearsagasman]

Changing the diaphragm is fairly straightforward. The push fit pipes held by circlips can be a bit tricky sometimes. Your diagnosis is almost certainly correct. Good luck with the repair.

 

[thetopcat84]

Thanks 45yearsagasman, part arrived today, had the distribution manifold out earlier. You weren't wrong about the clips btw, was very glad when I turned the water back on that all was sealed and secured.

Diaphragm was very worse for wear, had a hole in it. New one fitted nice and snuggly.

Reassembled, water back on, turned on hot water tap and could see the rod extend and close the micro-switch, but the boiler didn't fire up. Quickly realised I hadn't turned it back on at the plug socket

All in all it was an easy fix, trickiest part was getting the front control panel off (as the boiler is tucked right into a corner, so screwdriver access to the left screw was restricted).

Pretty chuffed that it was £3.25 all told! Much better than calling someone out for £80!!

 

[45yearsagasman]

Thanks for the feedback.

 

[gigz]

Quickly realised I hadn't turned it back on at the plug socket

Thats never happened to me before

 

[Fallout]

Changing the diaphragm is fairly straightforward. The push fit pipes held by circlips can be a bit tricky sometimes. Your diagnosis is almost certainly correct. Good luck with the repair.

Do you need new O-rings for the pressure pipes at the top?

 

[nickso]

Do you need new O-rings for the pressure pipes at the top?

Done loads of them, only had to change those o-rings once I think.

 

[Fallout]

Thanks, With the Vokera maxin is it best to remove the whole
Domestic Distribution Manifold to get access when replacing the diaphragm? The six screws holding the front cover on look hard to get to without removing the whole manifold?

 

[nickso]

Thanks, With the Vokera maxin is it best to remove the whole
Domestic Distribution Manifold to get access when replacing the diaphragm? The six screws holding the front cover on look hard to get to without removing the whole manifold?

isolate mains water.
remove the two pipes.
undo the two screws holding the manifold on.
remove manifold and undo screws.
make sure you note the orientation of the diaphragm etc when you disassemble. I clean the sealing rim on both halves...some lazy sods don't

refit is reverse of that pretty much.

make absolutely sure you are happy with the position of the clips that hold the pipes in, they clash together when fitted and are a bit crap. Seen more than a few fitted badly and just waiting for the pipe to slip out.

 

[Fallout]

Thanks is there a seal when I remove the two screw that hold the manifold on that needs replacing? I have the service kit but is it just the diaphragm I need from it really.

 

[Fallout]

is there an o-ring between the manifold that needs replacing before placing back in and tigthening the two grub screws?