Our gas oven is about 20 years old and I've just had to replace the
thermostat for the third time. The part is getting harder to find and is
consequently way more expensive (around £100) than it used to be.
Next time a new oven might be the better option.

Looking at thermostats for modern gas ovens (£35 or so) the copper tube
and phial/sender all look pretty much the same as mine. Is it possible
to change that - assuming that's what fails - rather than the whole
thing which includes the gas tap assembly?

Maybe it would need calibrating somehow but I'm not sure if it's
pre-pressurised. Guess I could take the old one apart but that may be
why it's failed if it lost pressure ...

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Reentrant

On 16/09/2016 14:18, Reentrant wrote:
Our gas oven is about 20 years old and I've just had to replace the
thermostat for the third time. The part is getting harder to find and is
consequently way more expensive (around £100) than it used to be.
Next time a new oven might be the better option.

Looking at thermostats for modern gas ovens (£35 or so) the copper tube
and phial/sender all look pretty much the same as mine. Is it possible
to change that - assuming that's what fails - rather than the whole
thing which includes the gas tap assembly?

Maybe it would need calibrating somehow but I'm not sure if it's
pre-pressurised. Guess I could take the old one apart but that may be
why it's failed if it lost pressure ...

I suspect the amount of valve movement is similar. Why not take your old
one part and investigate? The fault might not be obvious.

You might find some old "new stock" on ebay in the mean time for next time!

On Fri, 16 Sep 2016 14:43:00 +0100, Fredxxx wrote:

On 16/09/2016 14:18, Reentrant wrote:
Our gas oven is about 20 years old and I've just had to replace the
thermostat for the third time. The part is getting harder to find and is
consequently way more expensive (around £100) than it used to be.
Next time a new oven might be the better option.

Looking at thermostats for modern gas ovens (£35 or so) the copper tube
and phial/sender all look pretty much the same as mine. Is it possible
to change that - assuming that's what fails - rather than the whole
thing which includes the gas tap assembly?

Maybe it would need calibrating somehow but I'm not sure if it's
pre-pressurised. Guess I could take the old one apart but that may be
why it's failed if it lost pressure ...

I suspect the amount of valve movement is similar. Why not take your old
one part and investigate? The fault might not be obvious.

You might find some old "new stock" on ebay in the mean time for next time!

A couple of Ebay "saved searches" can work wonders for obscure items,
given enough time. Use a separate search with just the part number.

That's how I got a replacement gas valve for my (then) thirty year old
boiler. Fortunately it was hobbling along on its original valve so I
could wait.
It was the best part of a year until I got an email alert of one that
wasn't a silly price.




--

Graham.

%Profound_observation%

I've often wondered how such things work. The ones with a coiled tube and a
thicker end with a knob on one end and thethicker end in the oven always
seem to be crude to me. I wonder why even modern ovens use this over the
electronic alternative?
Brian

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"Fredxxx" wrote in message
...
On 16/09/2016 14:18, Reentrant wrote:
Our gas oven is about 20 years old and I've just had to replace the
thermostat for the third time. The part is getting harder to find and is
consequently way more expensive (around £100) than it used to be.
Next time a new oven might be the better option.

Looking at thermostats for modern gas ovens (£35 or so) the copper tube
and phial/sender all look pretty much the same as mine. Is it possible
to change that - assuming that's what fails - rather than the whole
thing which includes the gas tap assembly?

Maybe it would need calibrating somehow but I'm not sure if it's
pre-pressurised. Guess I could take the old one apart but that may be
why it's failed if it lost pressure ...

I suspect the amount of valve movement is similar. Why not take your old
one part and investigate? The fault might not be obvious.

You might find some old "new stock" on ebay in the mean time for next
time!

On 17/09/2016 09:01, Brian Gaff wrote:
I've often wondered how such things work. The ones with a coiled tube and a
thicker end with a knob on one end and thethicker end in the oven always
seem to be crude to me. I wonder why even modern ovens use this over the
electronic alternative?

The sensing end could easily be a thermistor but the electronic side
would have to endure a high temperature and you would need to drive a
gas valve as well as needing power.

A simple bulb of liquid which when expands has sufficient force to hold
off a valve seems incredibly simple and reliable to me.

Perhaps a thermopile? I have seen a gas fire use one in conjunction with
a conventional thermostat to turn the gas valve on and off.

On 17/09/2016 09:01, Brian Gaff wrote:
I've often wondered how such things work. The ones with a coiled tube and a
thicker end with a knob on one end and thethicker end in the oven always
seem to be crude to me.

Maybe crude, but I tested the new thermostat using an IR thermometer. At
gas mark 5 the oven temperature was right to within a couple of degrees
(375F).


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Reentrant