Gas cooker repair - oven flame won't 'woosh'

[Keith (Dorset)]

Dear all,

We have a twelve year old, or thereabouts, gas cooker of simple design. (Cleasea Moffat).

The oven will ignite and flames appear at all of the gas holes / nozzles.

The flame goes go up and down when the control knob is adjusted.

However, the oven flame/s no long 'woosh' - i.e. rapidly increase in intensity after a few seconds.

Is this something I can repair safely and easily? I am not a gas fitter. If so how?

If not, would it be feasible and non expensive to get a professional in to fix it.

Thank you in advance,

Keith

[R]

Dead thermocouple. Can be purchased from reputable gas plumbing merchants and fairly simple to change once you've located, undone, swapped out and reconnected. AFTER turning off the gas that is ;-)

[cynic]

Classic example of a reply from someone who "doesn't" know the answer but plunges in regardless!

Your oven flame failure device is the most likely problem. May not be a simple job so probably better to get a competent gas fitter rather than risk leaving a gas leak on the internal pipework.

[R]

Given that's what caused the same effect on mine I speak from experience

Instead of casting aspersions why not just quote your idea and be civil.

[Graham]

A classic response from someone who doesn't know that a thermocouple *is* a type of FFD

[R]

Hmmmm

Butthen *they* are all out there aren't they

[cynic]

quoted text -

Mainly because this guy will continue to offer wrong information until there is a problem!

The FFD on the oven in question is an expansion type where the heat of the starter flame causes a fluid to expand in a vial and exerts a force via a capillary to open the main oven burner gas supply. It is not a thermocouple. No doubt Ed will soon be along to confirm this. Some ovens do have thermocouple flame failure devices but it is neccessary to press and hold in a button or similar while lighting just like many old and not so old boilers with permanent pilot lights. The light small and fire up after a delay mostly use the above principle although a few bimetal strip versions may still be around.

[Ed Sirett]

Hide quoted text -

Talk of the devil...

I'm not familiar with this model so I don't know whether this is the more traditional low rate/high rate type oven valve (which I think it probably is based on the OPs description) or the more modern type of oven valve using a thermocouple to implement a FFD function.

If the OP had _not_ said the 'flames go up and down when the control knob is adjusted' I would have said check that the flame sensing bulb has not become displaced and failing that replace the entire oven gas valve (which will include the sensing bulb).

This latter job will almost certainly require very significant disassembly of the entire cooker and work on gas carrying parts. Quite probably outside the experience/competence envolope of the OP.

However I was hoping the OP would give us some more clues about the problem. He might have meant that the low rate flames are still controlled by the control knob i.e. off still does off. However there is no shift to high rate after a short while. He might have meant that after a while the flames are big enough toheat the oven and are controlled by the knob but they are not as big as they should be and/or he can't get the oven to do the higher setting.

I guess the bottom line is check the sensing bulb is in position and if it is call for help.

[Keith (Dorset)]

Hi Ed and others,

Very many thanks for your help, especially to Ed.

I think I meant that:

' the low rate flames are still controlled

however, we did manage to very partly cook a roast dinner, after one and a half hours (by which time it would normally have been cooked properly), so the oven is heating just a little.

Whatever, as it seems like there is no 'straightforward, safe, DIY fix... I won't try and mend this myself, and I will get in a Corgi fitter - or buy a new oven.

Thanks for all your help. I have learned a bit more anyway!

Keith