Bosch gas hob sparking when not switched on

[headache5678]

My Bosch Gas Hob E-Nr. PCD612CGB /01 had been sparking spontaneously when the hob gas knobs are switched off at irregular intervals but maybe hourly. I have cleaned all the burners and the whole gas hob and today I replaced the old ignition device (FZ4 f) with one supplied to me as an updated replacement (a TFZ4).

The above has made my problem worse. Instead of sparking spontaneously, of its own accord, but only every hour or two the sparking now occurs continually. Bizarrely, if I disconnect the earth lead from the earth terminal (numbered 3) on the new igniter device, the spontaneous sparking stops and the unit works as intended – i.e. only sparks when one turns any burner’s knob on. A picture of the ignition devices can be seen at : –

http://www.flickr.com/photos/27466575@N03/?saved=1

I wonder if the new igniter that I have been sold is not actually as compatible as it should be. Looking at the attached pictures it can be seen that the ART numbers, the CE numbers and the VA values (0.8 v 1.5) all differ.

Any steer or suggestions would be much appreciated especially re why would disconnecting the earth make a difference?

[Martin]

Re: Bosch gas hob sparking when not switched on

headache5678 wrote:Any steer or suggestions would be much appreciated especially re why would disconnecting the earth make a difference?

All sparker units are grounded to earth. The 4 individual ‘Ignitor Heads’ give a high voltage spark to ground (earth). It would suggest to me that the fault is that one (or more?) of those ignitors is possibly cracked and shorting to earth (i.e duff) :wink:???????????

[admin]

Re: Bosch gas hob sparking when not switched on

Hi

The most probable cause is that one of the switches has either got damp when cleaned or is stcky.

I cant see if you have an ignition web or a single swith but they both work the same. Live goes into the switch and out at the ignition box,the switch/ignition web is the only thing that could be faulty.

If you have a 4 burner hob then the spark generator will be 4 outlet if you have a 5 burner then it would be a 6 uotlet ignition unit and one lead would be grounded.

Bryan

[headache5678]

Re: Bosch gas hob sparking when not switched on

R600a and Martin,

Thank you. R600a may I confirm that I have a 4 burner model and a 4 outlet spark generator. I think the spark generator will effectively spark on all 4 poles at the same time i.e. it is not that sophisticated that it only sends a spark to the burner(s) to which gas is flowing, them having been turned on ?

R600a, may I ask – with rergards the dirty switch that I might try cleaning – do you mean clean each of the 4 knobs that turn the gas on to the burners ?

Shall I / where shall I order a new ignition device and the 4 ignition leads / heads anyway ? (I cannot find them listed on the UK Whitegoods site) .

Thank you
Kevin

[admin]

Re: Bosch gas hob sparking when not switched on

Hi

You wont need any ignition leads.The switch is either the button you press on the top of the hob or the wires that link together below the gas taps.Normally blue wires throughout.

Bryan

[Author]

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