Bosch PCD612CGB/01 Gas Hob - ignition problem

[headache5678]

My gas hob ignition sparks continuously - even if no ignition leads (igniter-> 4 burners) are connected - and the only way to stop it is to unplug the appliance. I have posted my problem on another site and done everything I can think of including:

- checking the appliance earth to the earth terminal on its mains plug

- replaced the ignitor,

- replaced all wiring switches (the loom that goes to all 4 burners)

- replaced 2 ignition leads

- cleaned everything

I am not totally convinced that the ignition is wired up correctly especially as the German instructions (with Schwartz and Rot descriptions on the brief wiring diagram) supplied with the new ignition unit do match up with my UK wiring colours or ways the wires go together.

Bosch - of course - will not supply me with a wiring diagram.

Any steer would be appreciated as I think the next step will be to buy a new hob.

 

[jj4091]

I am not really familiar with your hob, but I presume you either have a button that you press after turning on the gas or the burner knobs actuate a switch when you turn them, but either way it seems that you have a short circuit on the supply going to the ignitor( stuck switch or trapped or melted wire) do you have a multi meter so that you can resitance check the wires going to the ignitor?

 

[headache5678]

JJ you won't believe this but:

I found that the coloured wires had been reversed (by someone, not me) putting a extra bit of wire and thus switching the blue wire with the brown one).

The result of this was that the live brown wire was permanently feeding the ignition device, the neutral went through the switches and I guess the circuit was being permanently connected as the current passed through the permanently connected earth wire - without needing the neutral feed from the switch.

I have now switched the wires so that the live goes to the switches (a loom which provides a switch as one depresses each burner to turn the gas on) so the ignition device now only gets circuit current when a burner switch is on.

I cannot believe how this problem only seemed to surface a couple of months ago.

It was your tip to check the resistance with a meter which put me on to this and gave me the motivation to have one more try. I am very grateful.

May I ask one supplemental question - I switched the wires by using a couple of those small connector blocks, the plastic thingys with a brass connector inside so you tighten a small screw. The existing wires were not quite long enough to just put new "Lucar" ? connectors on the end. Is there any better gadget that I could / should use as a connector instead of these please ?

Thanks again

 

[jj4091]

crimp connectors would probably be better, or even soldered insulated joints if you have the facilities to do either, but if not screw connectors will be fine. Well done