In the past I have requested asssitance with the tendency of my gas
boiler ceramic pilot jet to become constricted with a hard dark
crystalline deposit. Well it has happend again and the pilot flame is
too weak to work the thermocouple.

I had prevoiusly been concerned about damage to the ceramic if I were to
scrape the deposit away. I now have a solution (literally). The black
gunge is dissolved by hot dilute sulphuric acid. A small amout in a
china mug, drop in the jet and place in the microwave. 15 seconds on
full power heats the acid whereas the amount of metal in the jet (being
very much smaller than the wavelength on the microwave) does not cause
any flashes and bangs.
A quick swirl round and rinse in lots of water yeilds a squeaky clean
jet.

I can now heat the water with the pilot alone (mild exaggeration
perhaps) and the thermocouple is once again happy.

Not a solution for the faint hearted but with sensible precautions (
like making sure SWMBO is not around!!) it does the job.

Oh yes - do wash the mug out before making a self congratulatory mug of
coffee!!

Regards

Bob

As you seem to be an expert on pilot lights any idea why the ones on my
cooker tend to keep firing? My gril is a grill / oven if you put it in to
oven mode the pilot light is automatically trigged, if its the grill i have
to do it manually. However its now decided when you put it to grill to fire,
and keep firing, only way to get it to stoop is not to use the grill on full
heat!
"Bob Minchin" wrote in message
...
In the past I have requested asssitance with the tendency of my gas
boiler ceramic pilot jet to become constricted with a hard dark
crystalline deposit. Well it has happend again and the pilot flame is
too weak to work the thermocouple.

I had prevoiusly been concerned about damage to the ceramic if I were to
scrape the deposit away. I now have a solution (literally). The black
gunge is dissolved by hot dilute sulphuric acid. A small amout in a
china mug, drop in the jet and place in the microwave. 15 seconds on
full power heats the acid whereas the amount of metal in the jet (being
very much smaller than the wavelength on the microwave) does not cause
any flashes and bangs.
A quick swirl round and rinse in lots of water yeilds a squeaky clean
jet.

I can now heat the water with the pilot alone (mild exaggeration
perhaps) and the thermocouple is once again happy.

Not a solution for the faint hearted but with sensible precautions (
like making sure SWMBO is not around!!) it does the job.

Oh yes - do wash the mug out before making a self congratulatory mug of
coffee!!

Regards

Bob

Thee_Psycho wrote:

As you seem to be an expert on pilot lights any idea why the ones on my
cooker tend to keep firing? My gril is a grill / oven if you put it in to
oven mode the pilot light is automatically trigged, if its the grill i have
to do it manually. However its now decided when you put it to grill to fire,
and keep firing, only way to get it to stoop is not to use the grill on full
heat!
"Bob Minchin" wrote in message
...
In the past I have requested asssitance with the tendency of my gas
boiler ceramic pilot jet to become constricted with a hard dark
crystalline deposit. Well it has happend again and the pilot flame is
too weak to work the thermocouple.

I had prevoiusly been concerned about damage to the ceramic if I were to
scrape the deposit away. I now have a solution (literally). The black
gunge is dissolved by hot dilute sulphuric acid. A small amout in a
china mug, drop in the jet and place in the microwave. 15 seconds on
full power heats the acid whereas the amount of metal in the jet (being
very much smaller than the wavelength on the microwave) does not cause
any flashes and bangs.
A quick swirl round and rinse in lots of water yeilds a squeaky clean
jet.

I can now heat the water with the pilot alone (mild exaggeration
perhaps) and the thermocouple is once again happy.

Not a solution for the faint hearted but with sensible precautions (
like making sure SWMBO is not around!!) it does the job.

Oh yes - do wash the mug out before making a self congratulatory mug of
coffee!!

Regards

Bob


I assume from your post that the pilot lights are not meant to be on all the
time? So what controls them? If it is an electrical/electronic circuit; perhaps
there could be a spillage that has got into the switch or perhaps some grease?
If the pilots are actuall lighting - this would indicate gas being present when
it should not be.

Sorry I can't be more helpful but the last gas cooker I had was as a child 40
plus years ago and this had a single central constant pilot light.

Bob

"Bob Minchin" wrote in message
...

Oh yes - do wash the mug out before making a self congratulatory mug of
coffee!!

Regards

Bob


.. . otherwise to old ditty might become:

"Toll the bell, toll the bell,
Bob Minchin is no more
For what he took for H 2 O
Was H 2 S O 4!"

Roger

Roger Mills wrote:

"Bob Minchin" wrote in message
...

Oh yes - do wash the mug out before making a self congratulatory mug of
coffee!!

Regards

Bob


. . otherwise to old ditty might become:

"Toll the bell, toll the bell,
Bob Minchin is no more
For what he took for H 2 O
Was H 2 S O 4!"

Roger

ROFL!

Thanks Roger

In all my 50years, that is the first time anyone has written (adapted) a poem
for me!

Bob

Bob Minchin wrote:

Thee_Psycho wrote:

As you seem to be an expert on pilot lights any idea why the ones on my
cooker tend to keep firing? My gril is a grill / oven if you put it in to
oven mode the pilot light is automatically trigged, if its the grill i have
to do it manually. However its now decided when you put it to grill to fire,
and keep firing, only way to get it to stoop is not to use the grill on full
heat!


I assume from your post that the pilot lights are not meant to be on all the
time? So what controls them? If it is an electrical/electronic circuit; perhaps
there could be a spillage that has got into the switch or perhaps some grease?
If the pilots are actuall lighting - this would indicate gas being present when
it should not be.

Sorry I can't be more helpful but the last gas cooker I had was as a child 40
plus years ago and this had a single central constant pilot light.


By "automatically triggered" I think you mean that you hear ignition
clicks which light the pilot light (and in due course allow the full
flow of gas)?

Cookers tend to be in one of two designs:
Either there is one manually operated knob for lighting all the burners.
Or on the better models each knob operates it's own sparker which is no
longer heard when the flame has lit because the flame shorts the sparker
out, (or maybe there is some electronics tyo detect this and stop the
spark unit).
Some models are half way between these design with an 'automatic
ignition' for the grill/over and manual for the hob burners.

I think it is likely that there is a fair bit of gunge on the oven/grill
knob which is now interfering with the switch for the ignition on same.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html