Rayburn royal running very hot

10 Nov 2012
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United Kingdom
My rayburn (oil fired) is suddenly running very hot. The bm30 control valve had an accidental knock, the system instead of running at 150 is now around 180.

I have checked and corrected the valve level, but no improvement.

Next would be to look at making a correction on the low fire screw on the valve. However on taking the top of the valve off I can't see either a high fire or low fire screw. This is an old valve and its gravity fed, so not sure if this makes a difference.

Can anyone help in identifying the low fire control? I have a picture of the top of the valve with the top off.
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Looking at the top of the oil control, the hig fire screw is the one towrards the rear edge of the OCV beyond the control knob,
The low fire screw is to the right of the control knob.

However I would not advice you to go adjusting these without really knowing what you are doing, as you can easily muck things right up!!

you are looking for a Low fire flow rate of 4.0 c.c./Min,
On high fire you are looking at around 11 c.c/min (after setting a visual check on flame shape and colour is required

You would be best getting an Experienced AGA/Rayburn engineer to do this for you! ;)
Thanks, sounds like good advice. Re low fire screw I have a lug hole by the control knob but no screw under the plate, same with the high fire, a hole and no screw. Also looks like there is metal under the hole, so guessing something is missing. I've looked at loads of tech specs but cannot find one to match.

Nothing else I can try is there before calling an engineer out is there?
The low fire screw setting has now been adjused and the rayburn temperature is now back to normal.

Thanks for all the help :D
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What I should have also said is the low and high fire screws were at either end of the ratchet, which controls the oil flow. They are tiny, and are not the large screws on the models shown in the later technical specs.
If the BM control had been knocked, then adjusting the low fire screw is probably not treating the fault. A knock has probably altered the level of the float control, and therefore the oil level in the burner. You probably now have a dirty flame which will make the cooker sooty.

A wise man at Aga once said the only problem with BM controls is the nut that holds the screwdriver.

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