Biasi 24S DV - Diaphragm replaced still not igniting.

[Imtoo]

Hello

I have had a long term problem with my boiler.

Went through a few months where the Hot water only worked if Central Heating was on.

With the recent hot weather we turned all the radiators off, and all was fine for around 2 months and we had hot water which was ok, but now the boiler wont ignite and just makes the same sound it did when when the rads were hot and it didn't need to pump.

From my research the problem seems to be with the diverter valve but I don't know which bit that is, and as I'm so cash poor at present I cannot afford to get someone into repair/replace it.

View media item 25602
Is the diverter valve the part that I have circled in red ?

And what steps should I take before I open it up to replace the diaphragm.

Should I drain the whole system etc ?

Thanks

 

[kevplumb]

the part in the pic is the water section of the diverter

sounds a good place to start

you need to turn off the cold feed and drain it before you start

 

[Imtoo]

Hi

Thanks for the reply.

As you can see in the picture below the diaphragm is no good and needs replacing.

View media item 25704
I shall go to plumbcentre and get a replacement asap.

Before I started the disassembly I asked someone in b&q what flushing agent I should use and he didnt have a clue (surprise, surprise ) so I bought Sentinel x800 which I'm not sure of so will check the forums for that info. After which I will use the x100 inhibitor.

My next question though is how do I get it into the system without any special pump etc?


Thank You

 

[Imtoo]

Hello

I have replaced the diaphragm but it's still not igniting, it makes all the usual noises but just doesnt start up.

Any ideas what it might be ?

Thank You

 

[treefella]

Anyone have some ideas what to test next?

This is be my brother, I told him this was the place to get help

Cheers guys!

 

[treefella]

bump

 

[Gasguru]

How far does it get...

Does the pin at the other end of the diverter operate the microswitch?

Does the pump run?

Does the fan run?

etc

etc

I guess you've checked the overheat stat button hasn't popped out.

 

[treefella]

None of those things have been checked. I am there now, and unfortunately neither of us know much about boilers, so not sure where the switch and fan are that you mention.
Pump is running.
I see one pin pushing into the switch that is nearest the left. The other switch/pin is hidden by the box in front of it. I will try get a mirror in there to see if the pin is moving. and post back.

Cheers.

Edit: Ok, I could see the pin is not pushing out into the micro switch. The pump is working as I can here the water moving through the rads.
Just a buzzing sound but nothing firing up.

He doesn't have the book for the boiler, so I can't see where to check if the 'overheat' cutout switch needs reseting.

Thanks.

 

[OLLIE20]

Does heating work? if yes it hasnt o/htd.

Have you fitted diaphragm the correct way?

Whats the water pressure like, any recent change?

The diaphragm in your pic deffo nackard, so hopefully not the full vave, although you can get service kits for these anyway

 

[transam]

Pump running ?? the primary flow switch micro switch is not making via the pin , untill this makes ignition sequence will not start !!

 

[OLLIE20]

He said the pump flow switch is making, transam

 

[treefella]

He fitted the new rubber diaphragm so it was snug , parallel to the left side. This could be the problem then.
I will drain down and strip that part off again. Waiting for confirmation before I reverse it.

(No heating or h/water. Pump running)

Cheers guys, really appreciate you taking the time to help out.

 

[OLLIE20]

Can you see if the DHW microswitch behing the gas valve and ignition box is making, if it isnt you have a problem with diverter somewhere.

I'm not 100% if there is a manual o/ht stat on these, perhaps someone will know, is there not a white or black screw cap on front pannel nex to control knobs, with a flat slot in it? If yes, unscrew it and push the little button underneat it, that is your o/ht

Did it work when you 1st fired it back up, after changing part, was CH ok before?

 

[transam]

He said the pump flow switch is making, transam

Yep he did , must read things better than again I always say that !

 

[treefella]

Maybe this will help, as I don't know the actual names of the parts.