Been fault finding on my old combi and having solved the problem I would like to share the solution with those who are still running the old Baxi Water Hotter!
Model of boiler is BAXI 105E combi - Not a condensing combi. This model is around 20 years old.
Nature of fault - No hot water, fan failure fault light on, and flame failure fault light on.
I initially changed the complete diverter valve assembly because the original one was leaking and badly corroded, although this was not actually causing the fault.
I traced the fault to a relay on the pcb which actuates the fan. For information, the relay is marked RL.1
This applies to a Honeywell pcb with the following markings printed on it -
CE 00518L 1810
CS0118E-LS
TYPE:MIDINT00
CD 995099 2
CD 565599 2
I sourced a replacement relay from ebay, in fact I bought 2, since there are 2 identical relays on the pcb so I got a spare.
Relay part no details -
TAKAMISAWA JV24S-KT
5A 30VDC
250VAC
SPST
Coil voltage is 30VDC, cantact voltage rating is 250VAC
I unsoldered the original relay and connected 30VDC across the coil and a multi-meter set to ohms across the contacts - result was open circuit.
I repeated the process with the new relay and got continuity across the contacts and a satisfactory click as the coil energised.
I had a spare pcb but that didn't work at all when I just did a straight swap. Anyway I hope someone finds this info useful.