Vaillant 142

[Agile]

I have a friend with one of these.

It has power at the input, a call for heat but does not do anything at all.

All the external devices seem correct but without a circuit diagram for the three part PCB it will be very time consuming for me to trace the fault.

Does anyone have detailed electronic information or can point me to a component failure which would cause this problem?

Tony

 

[geoff@cetltd]

You really mean 142, not 242 ?

 

[kevplumb]

try 242 E

 

[geoff@cetltd]

if you want to be pedantic ...

E ot EH ?

I just wanted to check that there is no 142, as I've not heard of it

I have cct diagrams and circuit boards for both the 242E and 242EH
the pcb sets which while looking similar are somewhat different

Tony, you'd best take this to email

 

[Agile]

It really is a VC GB 142 EH if you want to be pedantic. I have seen several of them!

It has the apparently similar to the 242 series of three PCbs with the Vaillant part numbers:-

130451
130330
252957

Its a heat only boiler with an exp vessel full height on the left!

Tony

 

[geoff@cetltd]

motherboard, hybrid thermostat board and fan ctrl board ?

I can have a look through my vaillant documentation on monday

I can prolly lend you a set of boards to play with

 

[croydoncorgi]

Looks like you'll have to spend £25 and get the manual Tony!

Hints from manual fault tree:
After resetting the cut-out (!) and confirming call-for-heat on terminals 4/5, does pump run? If not check pump terminals for voltage and unjam if present. If no volts and red neon on, try resetting neon. If it won't reset, replace FSD board. If no red neon, select pump position 1 *. If it now runs, replace thermostat PCB, if not, replace main switch PCB. If won't run with pump position 1, replace main switch PCB, then themostat PCB.
If / when pump DOES run, check fan (which should also be running!) and APS, then move on to ignition system.

* that's what it says -no idea what it refers to!!

 

[Agile]

Those words could actually be a little helpful John.

The pump does not run and the cutout mechanically resets but its a four terminal device. Probably main circuit and auxillary contacts but they appear to be correct.

I am expecting its a fault on the thermostat pcb but its arrangement makes live faultfinding in situ very difficult.

Anyone know which is the pump relay as it may be a coil failure on that.

Tony

 

[ChrisR]

Have sets of hybrid/ non hybrid boards somewhere, will have a look.
Sending you a pdf, so you'll probably beat me to it.

 

[namsag]

If your not competent enough to work on one of these boilers don`t touch it and get a corgi registered guy to look at it for you . Not my personall opionion but opinion of one of guys who posts on here and doesn`t like to give basic advice. For life of me his name escapes me .

 

[geoff@cetltd]

"If no volts and red neon on, try resetting neon. If it won't reset, replace FSD board"

it doesn't have one according to the pcb numbers Agile posted yesterday

"If your not competent enough to work on one of these boilers don`t touch it and get a corgi registered guy to look at it for you . Not my personall opionion but opinion of one of guys who posts on here and doesn`t like to give basic advice"

ha ha VBG