Hi folks,

Our gas oven (New World, 20+ odd years old) is being reluctant to heat
up.

Old behaviour: Turn knob oven to required setting, a bit of clicking,
flame lights, few seconds and then it grows top full size , heats up
oven.

New behaviour:

Turn on, flame lights, just sits there indefinitely on low, oven doesn't
get very warm. However if you open the oven door after the flame lights,
after a wait (10-20 seconds?) the flame goes to full size, shut door and
oven heats. It seems to be heating it to the correct temp.

There is an additional quirk. If the oven is used at a higher temp (say
Mark 6), then reduced to a lower temp (say mark 4) the flame doesn't
kick back in to warm up again the oven once it's cooled down past mark
4.

I had a peer in the back of the oven and can't see anything obvious. any
thoughts folks?

Thanks

--
Chris French

Chris French wrote:

Hi folks,

Our gas oven (New World, 20+ odd years old) is being reluctant to heat
up.

Old behaviour: Turn knob oven to required setting, a bit of clicking,
flame lights, few seconds and then it grows top full size , heats up
oven.

New behaviour:

Turn on, flame lights, just sits there indefinitely on low, oven doesn't
get very warm. However if you open the oven door after the flame lights,
after a wait (10-20 seconds?) the flame goes to full size, shut door and
oven heats. It seems to be heating it to the correct temp.

There is an additional quirk. If the oven is used at a higher temp (say
Mark 6), then reduced to a lower temp (say mark 4) the flame doesn't
kick back in to warm up again the oven once it's cooled down past mark
4.

I had a peer in the back of the oven and can't see anything obvious. any
thoughts folks?

Thanks


I was gonna say that the main thermostat that regulates the gas must be
faulty but then I saw this.
http://www.ebay.co.uk/gds/Gas-oven-w...0811842/g.html

Could be either I suppose.

Tim

--
Trolls AND TROLL FEEDERS all go in my kill file

On 12/06/2016 20:46, Tim+ wrote:
Chris French wrote:

Hi folks,

Our gas oven (New World, 20+ odd years old) is being reluctant to heat
up.

Old behaviour: Turn knob oven to required setting, a bit of clicking,
flame lights, few seconds and then it grows top full size , heats up
oven.

New behaviour:

Turn on, flame lights, just sits there indefinitely on low, oven doesn't
get very warm. However if you open the oven door after the flame lights,
after a wait (10-20 seconds?) the flame goes to full size, shut door and
oven heats. It seems to be heating it to the correct temp.

There is an additional quirk. If the oven is used at a higher temp (say
Mark 6), then reduced to a lower temp (say mark 4) the flame doesn't
kick back in to warm up again the oven once it's cooled down past mark
4.

I had a peer in the back of the oven and can't see anything obvious. any
thoughts folks?

Thanks


I was gonna say that the main thermostat that regulates the gas must be
faulty but then I saw this.
http://www.ebay.co.uk/gds/Gas-oven-w...0811842/g.html

Could be either I suppose.

I had assumed it was the Flame Failure Device.

If it is the New World oven I think it is, there is a shield in front if
the burner that can be removed. Check the integrity of the burner, I
suspect some food crud has dropped onto the burner, possibly now
carbonised and has blocked some holes.

Fredxxx wrote:
On 12/06/2016 20:46, Tim+ wrote:
Chris French wrote:

Hi folks,

Our gas oven (New World, 20+ odd years old) is being reluctant to heat
up.

Old behaviour: Turn knob oven to required setting, a bit of clicking,
flame lights, few seconds and then it grows top full size , heats up
oven.

New behaviour:

Turn on, flame lights, just sits there indefinitely on low, oven doesn't
get very warm. However if you open the oven door after the flame lights,
after a wait (10-20 seconds?) the flame goes to full size, shut door and
oven heats. It seems to be heating it to the correct temp.

There is an additional quirk. If the oven is used at a higher temp (say
Mark 6), then reduced to a lower temp (say mark 4) the flame doesn't
kick back in to warm up again the oven once it's cooled down past mark
4.

I had a peer in the back of the oven and can't see anything obvious. any
thoughts folks?

Thanks


I was gonna say that the main thermostat that regulates the gas must be
faulty but then I saw this.
http://www.ebay.co.uk/gds/Gas-oven-w...0811842/g.html

Could be either I suppose.

I had assumed it was the Flame Failure Device.

If it is the New World oven I think it is, there is a shield in front if
the burner that can be removed. Check the integrity of the burner, I
suspect some food crud has dropped onto the burner, possibly now
carbonised and has blocked some holes.
I've no relevant experience on gas ovens but I'm surprised that any
flame failure device would allow and gas to continue to flow?

I seem to recall that some ovens have a device to turn down the gas when
the door is opened. It sounds like yours has this - and it could be
sticking or failing.

I believe it is to prevent the heat from taking off your eyebrows when you
open the door with the burner on full. It may also be an anti-suicide
device!

On 13/06/2016 10:30, Bob Minchin wrote:

I've no relevant experience on gas ovens but I'm surprised that any
flame failure device would allow and gas to continue to flow?

I think on my gas oven the FFD and thermostat seem to work in partnership.

1) Turn on oven - no flame but series of sparks from igniter across part
of the burner.

2) small "pilot flame" springs into action that seems to be directed
towards a small bulb- but no flame from the main burner

3) About ten seconds later big "wumph" as main burner lights.

4) when oven up to temp main burner flame is very low but much bigger
than in (2) above.

In (4) I assume that the FFD is open but thermostat turned right down.
in (2) I assume that FFD is initially closed but Thermostat would be
fully open.


--
Chris B (News)

In message 6,
DerbyBorn writes
I seem to recall that some ovens have a device to turn down the gas when
the door is opened. It sounds like yours has this - and it could be
sticking or failing.


Thanks,

Butl it has never turned down the flame before. So it probably hasn't
got that function.

--
Chris French

In message , Chris B
writes
On 13/06/2016 10:30, Bob Minchin wrote:

I've no relevant experience on gas ovens but I'm surprised that any
flame failure device would allow and gas to continue to flow?

I think on my gas oven the FFD and thermostat seem to work in partnership.

1) Turn on oven - no flame but series of sparks from igniter across
part of the burner.

2) small "pilot flame" springs into action that seems to be directed
towards a small bulb- but no flame from the main burner

3) About ten seconds later big "wumph" as main burner lights.

4) when oven up to temp main burner flame is very low but much bigger
than in (2) above.

In (4) I assume that the FFD is open but thermostat turned right down.
in (2) I assume that FFD is initially closed but Thermostat would be
fully open.


Mine works in a similar way except it doesn't have a pilot flame, it
just seems to light the main burner at a low level (as it is when the
oven is up to temp.) then it turn the flame on full.

I did wonder about a faulty FFD, but couldn't work out what failure mode
would lead the observed behaviour (will light once the door is open, but
not if it shut. The flame is behaving the same. Unless there was some
sort of oxygen sensor as well?



--
Chris French

On 13/06/2016 19:47, Chris French wrote:


Mine works in a similar way except it doesn't have a pilot flame, it
just seems to light the main burner at a low level (as it is when the
oven is up to temp.) then it turn the flame on full.

I did wonder about a faulty FFD, but couldn't work out what failure mode
would lead the observed behaviour (will light once the door is open, but
not if it shut. The flame is behaving the same. Unless there was some
sort of oxygen sensor as well?



Me neither. But I did just wonder if the FFD/FSD is very near to [total]
failure but not quite there yet. So opening the door increases the air
supply, and that allows the "pilot flame" to heat the tip of the device
just that bit more, and so open the valve to pass gas at the full rate.

I have tested this in the past by turning on the oven and then applying
a bit more heat to the tip using a long gas lighter - one like this

http://www.johnlewis.com/tala-gas-li...&tmcampid=7 3

But I am sure that was foolish behaviour so cannot possibly recommend it.

And it still doesn't give a convincing explanation as to what happens
when the thermostat reduces the supply.

--
Robin
reply-to address is (intended to be) valid

On Sunday, June 12, 2016 at 8:14:05 PM UTC+1, Chris French wrote:
Hi folks,

Our gas oven (New World, 20+ odd years old) is being reluctant to heat
up.

Old behaviour: Turn knob oven to required setting, a bit of clicking,
flame lights, few seconds and then it grows top full size , heats up
oven.

New behaviour:

Turn on, flame lights, just sits there indefinitely on low, oven doesn't
get very warm. However if you open the oven door after the flame lights,
after a wait (10-20 seconds?) the flame goes to full size, shut door and
oven heats. It seems to be heating it to the correct temp.

There is an additional quirk. If the oven is used at a higher temp (say
Mark 6), then reduced to a lower temp (say mark 4) the flame doesn't
kick back in to warm up again the oven once it's cooled down past mark
4.

I had a peer in the back of the oven and can't see anything obvious. any
thoughts folks?

Thanks

--
Chris French

If it's that old, time for a new one?

" Wrote in message:
On Sunday, June 12, 2016 at 8:14:05 PM UTC+1, Chris French wrote:
Hi folks,

Our gas oven (New World, 20+ odd years old) is being reluctant to heat
up.

Old behaviour: Turn knob oven to required setting, a bit of clicking,
flame lights, few seconds and then it grows top full size , heats up
oven.

New behaviour:

Turn on, flame lights, just sits there indefinitely on low, oven doesn't
get very warm. However if you open the oven door after the flame lights,
after a wait (10-20 seconds?) the flame goes to full size, shut door and
oven heats. It seems to be heating it to the correct temp.

There is an additional quirk. If the oven is used at a higher temp (say
Mark 6), then reduced to a lower temp (say mark 4) the flame doesn't
kick back in to warm up again the oven once it's cooled down past mark
4.

I had a peer in the back of the oven and can't see anything obvious. any
thoughts folks?

Thanks

--
Chris French

If it's that old, time for a new one?


Well yes, thing is kitchen is awaiting a refit, but it',s not
happening just yet, so am trying to avoid buying a new
one.
--
--
Chris French