Gas hob ring not staying alight help identifying parts

[PeterCarole29]

Found one ring on my hob will light but not stay alight . Can anyone help to identify the parts I might need and where to buy them from
I have taken a photo and if it’s any help it’s in a knaus

 

[B+W vanman]

Found the hob not lighting can anyone help to identify the parts I might need and where to buy them from
I have taken a photo and if it’s any help it’s in a knaus



View attachment 1036813

View attachment 1036814

There’s a difference between not lighting and not staying alight
And do the other burners work?

 

[PeterCarole29]

There’s a difference between not lighting and not staying alight
And do the other burners work?

Thankyou your right a bad description
Yes the others light and stay a light
One in the photo lights but will not stay a light
I suspect it’s the thermo coupling but I am not familiar with this hob

 

[Purrfecttune]

Ours isn’t the same but we had a similar problem.

I dismantled the burner pieces and blew as hard as I could into it. (Alternatively you could try using a strong suction hoover on it). I also cleaned everything as best as I could with gentle use of a green scourer. This cured our problem and I think that maybe it had ash, carbon or food deposits in it somewhere.

 

[oldiesontour]

If it lights and burns normally ,but then goes out when you release the knob it is thethermo couple

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[Purrfecttune]

If it lights and burns normally ,but then goes out when you release the knob it is thethermo couple

Not in our case it wasn’t (maybe a rarity)

Maybe me cleaning the thermocouple was the answer?

 

[LithiumConvert]

If it lights and burns normally ,but then goes out when you release the knob it is thethermo couple

first simple check.
is the thermocouple in the flame? (check for difference with the other burners)

 

[B+W vanman]

Not in our case it wasn’t (maybe a rarity)

Maybe me cleaning the thermocouple was the answer?

Or cleaning the flame spreader so that the necessary envelopment of the tip of the thermocouple with the flame happened?

 

[Purrfecttune]

Or cleaning the flame spreader so that the necessary envelopment of the tip of the thermocouple with the flame happened?

Yeah, could be?

 

[PeterCarole29]

Ours isn’t the same but we had a similar problem.

I dismantled the burner pieces and blew as hard as I could into it. (Alternatively you could try using a strong suction hoover on it). I also cleaned everything as best as I could with gentle use of a green scourer. This cured our problem and I think that maybe it had ash, carbon or food deposits in it somewhere.

I shall look into doing this
Did you ever look at where parts can be bought

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[PeterCarole29]

first simple check.
is the thermocouple in the flame? (check for difference with the other burners)

Yes it does appear to be in the flame

 

[PeterCarole29]

first simple check.
is the thermocouple in the flame? (check for difference with the other burners)

They all are burning Blue and the same

 

[PeterCarole29]

I would like to try and find replacement parts before dismantling and swooping things round just in case I end up with 2 burners not working

 

[PeterCarole29]

Does anyone know why there are 2 wires ( I call them wires as not sure how to describe them )
One seems to be acting as an earth or circuit link via the body or am I thinking rubbish

 

[B+W vanman]

Does anyone know why there are 2 wires ( I call them wires as not sure how to describe them )
One seems to be acting as an earth or circuit link via the body or am I thinking rubbish

I think that the insulated wire is connected to the spark-generator on the gas-valve, and the thin “capillary” tube is the thermocouple connection. I am not a registered gas engineer, so be careful!
Perhaps the thermocouple and spark are combined in one fitting that is attached to the burner body and replaced in one component? If you search for Dometic or Knaus thermocouple on eBay you’ll see what I mean- about £50 as they are Dometic!
Second thought- I think I may be living in the past, and the flame protection devices nowadays are technically thermistors, not thermocouples. That means they work by passing a tiny electric current through the flame - no flames= no current = gas valve shuts.
That’s why sometimes a good clean of the thing works

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[AJM2]

This tip worked for me last week when I had exactly the same problem:
After lighting the burner, release and push back in (fast) 3 or 4 times.
Repeat the process a few times. Mine stayed alight after 3 goes.

 

[Shrimp]

Ours often gave trouble either not lighting or not staying alight all they needed was a clean out.

 

[PeterCarole29]

I think that the insulated wire is connected to the spark-generator on the gas-valve, and the thin “capillary” tube is the thermocouple connection. I am not a registered gas engineer, so be careful!
Perhaps the thermocouple and spark are combined in one fitting that is attached to the burner body and replaced in one component? If you search for Dometic or Knaus thermocouple on eBay you’ll see what I mean- about £50 as they are Dometic!
Second thought- I think I may be living in the past, and the flame protection devices nowadays are technically thermistors, not thermocouples. That means they work by passing a tiny electric current through the flame - no flames= no current = gas valve shuts.
That’s why sometimes a good clean of the thing works

Thats where i,m baffled there is no ingniter or wiring anywhere to sggest there ever was
On other hobs when theres an igniter i have seen 2 stems on the top newt to the ring one has a ceramic outer .There only one the thermo stem

 

[B+W vanman]

View attachment 1036990

Thats where i,m baffled there is no ingniter or wiring anywhere to sggest there ever was
On other hobs when theres an igniter i have seen 2 stems on the top newt to the ring one has a ceramic outer .There only one the thermo stem

That’s why I think the thing is dual purpose, the spark passes through the “thermo” stem and the sensor current flows through the return wiring to maintain the gas flow.
I would try the respark when lit trick and/or clean the burner and thermo stem first, see if that works before replacing anything

 

[PeterCarole29]

That’s why I think the thing is dual purpose, the spark passes through the “thermo” stem and the sensor current flows through the return wiring to maintain the gas flow.
I would try the respark when lit trick and/or clean the burner and thermo stem first, see if that works before replacing anything

Yes will try cleaning first, If you study the photo and follow the wires back to each point do you still think its part of an ignition system because i cannot see anthing that would go to an igniter box

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[B+W vanman]

Yes will try cleaning first, If you study the photo and follow the wires back to each point do you still think its part of an ignition system because i cannot see anthing that would go to an igniter box

I think on mine there is a separate spark generator somewhere, powered by the 12v system which connects via the gas valves manifold to each individual thermo-stalk via the insulated wire that comes from the valve body
I think if you undo the shroud around the burner body on the top, you’ll see the stalk as the spark path, with the spark jumping to (or from!) it.
I too remember the ceramic coated electrode spark systems with separate thermocouples- times change!

 

[PeterCarole29]

View attachment 1036990

 

[PeterCarole29]

I have fixed it
The electrode was touching the aluminium collar under the burner top

 

[B+W vanman]

I have fixed it
The electrode was touching the aluminium collar under the burner top



View attachment 1037129

Congrats!

 

[PeterCarole29]

Now it’s not and works

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[PeterCarole29]

Thanks for all your replys

 

[B+W vanman]

Now it’s not and works



View attachment 1037131

Was the electrode/thermistor bent? Or just dislodged?

 

[PeterCarole29]

Non of those I forced the thick aluminium round top plate 1 mm so it wasn’t touching the electrode
I thought if one of the wires was an earth or forming some sort of circuit it would logically want to not be touching if that makes sense. Very much trial and error
As it worked I didn’t need to do anything else

 

[PeterCarole29]

The electrode was firm in its position quite upright and tight not loose in any way