Worcester 24cdi no hot water

[nabby68]

So today I have no hot water not heating side is fine. I have a Worcester 24cdi combi.
So after a bit of advice that it’s probably the diaphragm on the diverter valve I set about replacing it. 8 hrs later and wat a b***h of a job that was! Anyway no leaks so I power up and still no hot water!
So starting to think it could be the micro switch on the diverter valve. Should I heat it click if it’s ok??
Any help appreciated

 

[Dan Robinson]

Yes you should hear a click.

 

[mcmoby69]

See if black cap is still on the end of the spindle inside the microswitch, it might have dropped off.
If it's still there, open hot water tap and see if it moves all the way over.
Could be gummed up diverter valve, or missing/broken restrictor in the back of the plate heat exchanger.

 

[Cgas]

Definitley didn't miss putting anything back in such as the spring?

 

[nabby68]

Ok thanks for all your help. I’ve not missed putting anything back. Also, one thing that did happen is the micro switch got a bit wet when I removed it from valve. Could this have made it short when powered up?

 

[nabby68]

With regards to the switch. Does that push the black cap over on the diaphragm?

 

[Hot&Cold]

You could take the switch off the diverter valve and push the contact area with a screwdriver and see the boiler hw demand light illuminates and then fires the boiler.

 

[nabby68]

Is the contact area the small black disc?
Also if I take the micro switch off and then switch the boiler control to DHW would I be able to see the switch activate?
Also does the switch operate the diaphragm or does the diaphragm operate the switch?

 

[MTCH]

Does the pin move out when you place a demand for hw, as its unusual for the microswitch to fail on these tbh.

 

[nabby68]

Not had a chance to check it as I’m in work today. So let me get this right.
When there is demand for hot water, the diaphragm moves the pin which activates the switch which kicks the boiler in?
And is it possible for me to view the pin without having to remove the heat exchanger?
Also, what else could it be if it’s not the diaphragm or switch?

 

[MTCH]

You can position the microswitch so that the pin is visible then view it from underneath. As somebody has already said, also make sure that the plunger is still attached to the end of the pin.

 

[mcmoby69]

Turn hot tap on, check if spindle with black cap on touches and operates the micro switch. If it doesn't there's an issue with the diverter, could be as I said before.

Gently insert a screwdriver to operate the micro switch, does it fire?
If it does, keep the screw driver in there leave it running for a few seconds, does the flow pipe for the central heating get hot? If it does, the back end of your diverter is gummed up.

If you have a shower fed off the combi you could have a back feed through the non return valve on the hot side which could produce similar symptoms.

 

[nabby68]

Gently insert a screwdriver to operate the micro switch, does it fire?
If it does, keep the screw driver in there

Thanks for your reply. When inserting the screwdriver am I looking for some kind of switch to operate.
Would this be better observed with the micro switch removed?
Luckily we have an electric shower. Although the water was luke warm last night when we had the heating on for a bit

 

[Hot&Cold]

When inserting the screwdriver am I looking for some kind of switch to operate.

 

[nabby68]

Thanks for that video old&cold. Is it important that the switch stays together because when I took mine off the casing came apart which looked natural to me and not that it had split. So when I put the switch back on I just put the plastic casing of the switch back together