Performa 28 - CH, but no DHW

[Brigadier]

Hello All,

Diverter has been passing a bit for a while (bathroom rad heating after prolonged use of thermostatic shower).
Last night, shower ran cold, as did all hot taps.
I reset boiler - no fix.
No loss of pressure, nor leaks that I can see.
Boiler doesn't fire up when DHW demanded.
PCB was replaced earlier in year.

Diverter?
Diaphragm?
Demand switch?
PCB?
All / none / some of the above, and / or anything else?

Any other diagnostics / tests I ought to do?

Thanks in anticipation

 

[twgas]

Diaphragm sounds most likely if HW suddenly stopped, but with diverter already known to be passing, that ought to be sorted at the same time.

 

[Brigadier]

Many thanks! Is the diaphragm a relatively simple fix? (I already think the diverter is beyond me)!

 

[Brigadier]

1/8th inch split in diaphragm - 20 min., and £14 fix
Relly wot fixed it advised to change diverter when christmas period is over.
Thanks again!

 

[East Kent Coastal]

You may not have to change the divertor as it passing could've been caused by the ripped diaphragm so may be solved too. Test again by running a hot tap for a bit on a cold CH system and feeling the larger lefthand pipe about a metre away from the boiler.

 

[Brigadier]

I did consider that possibility, but the bathroom radiator warmed up after I had had a shower. Still CH and DHW - I'm happy!