Gas hob problem

[DiyNutJob]

I have a problem with a gas hob where the igniter spark comes on by itself every few minutes without the igniting knobs being used. This could be a problem with one of the knobs. Is DIY fix for this allowed? It may or may not be related, but one of the 4 cooking "rings" never sparks.

The problem could also be more serious. How much risk is there for the electrically/electronically controlled gas valves to the cooking rings to open by themselves?

Is there any regulations that says I can't turn off the mechanical mains gas valve below the hob myself?

Thanks a big bunch.

 

[foxhole]

Gas valves are not controlled electrically , just produces a spark to ignite .Grease can cause knobs not to release completely , take them off and give a good clean .

 

[DiyNutJob]

Thanks. I saw what's under and the valves to individual rings are mechanical. So, there is no risk of the valves opening by themselves.

There is a gasket between the hob cover and where it mates the ring base. I presume it's made from special heat resistant material. Any idea what kind of gasket it is? I want to get a generic piece and cut and hole myself.

 

[DiyNutJob]

The spark not working on one of the burn rings is to do with the distance of the electrode. That's easily enough to fix. The intermittent uncontrolled spark isn't fixed, but likely to do with one of the ignition switches failing.

The gasket I am interested to replace is pictured. It's papery, leathery, and probably fibrous. Anyone knows what materials is this and what kind of temperature it is expected to handle in that position under the hob cover? Buying the original part is unlikely as it is an old hob. The gasket is estimated to be 0.8mm thick.

 

[CBW]

As suggested have a look under the control knob, not the burner ring. The gasket may be considered gas work as it’s maintenance.

 

[opps]

I have a problem with a gas hob where the igniter spark comes on by itself every few minutes without the igniting knobs being used.

My last gas hob would do that for a day or two after cleaning it. I just put it down to the water used to clean it creating a bridge that resulted in constant clicking.

 

[DiyNutJob]

As suggested have a look under the control knob, not the burner ring. The gasket may be considered gas work as it’s maintenance.

I would have thought the gasket is more of a paper work. It's not there to seal the gas. It's there to seal against cooking spills. Do you reckon Flexoid is good enough? It's for oil and water, but nothing about temperature.

.. just found out flexoid is rated for 120°C. It does look the right colour. The high temperature gaskets are blue or grey for 250C continuous.

 

[DiyNutJob]

My last gas hob would do that for a day or two after cleaning it. I just put it down to the water used to clean it creating a bridge that resulted in constant clicking.

I am no expert. But I believe hob igniters use inductive switches for their water proof characteristic. Over time, the spring that keeps the trigger away becomes weak resulting in the trigger hovering close to the triggering distance. This is one possibility. The other possibility is the sealed electrical coil degrades from age and modifies the triggering distance. This then triggers the switch.

How inductive switches work, water should have no effect:

 

[DiyNutJob]

The uncontrolled sparking fixed by itself. Most likely one of the triggers did not fully return to the off position because of debris. The debris must have been dislodged when the hob cover was manipulated.