Rayburn 480k MX - Boiler will not ignite

Finally got hold of an engineer, who serviced the machine and replaced the air pressure switch. Still a few strange glitches but at least running now. Bill hurt but we are warm. Thanks for everyone's input. - John

"Air pressure switch ?" just confirms I know nothing about these particular twin burner Rayburns, and at my age I am not going to try to find out either. LOL

Thanks John. I didn’t realise there was a pressure switch on these either. A course would obviously help me lol.

Thanks again

@Gone-on-John I’ve just noticed the start up sequence image you posted (didn’t see it at first). That’s very helpful, it tells me what’s happening and when. Where did you find this image? Could you provide a link so I can have a further study of rest of manual?

The diagrams are from the service manual that came with the appliance. I have scanned a few pages and attached them. It is a bit big to scan all of it, do you have any bits you would particularly like to see? I would have thought that there was a downloadable version on the Rayburn site. - John

Thanks very much John. These screen shots tell me virtually all I wanted to know. When you attached the burner sequence image yesterday I studied it and noticed that when boiler burner runs two motors are energised and only one when cooker burner is live. I assumed at the time the cooker motor is supplying cooker fan and pump and the boiler motor just a fan. Reading what you just attached confirms my thinking. One last thing I’m curious of and that you might be able to find is how the soft start pressure is governed. These pumps have a single regulating spool inside them, with the theory of say 10 bar setting at pump = 10 bar at nozzle but as you know the soft start on this unit is 6 bar so unless I’m being stupid there must be something else initially adjusting this pressure.
Thanks for taking the time so I can get a better understanding of these units, much appreciated and I’m glad you managed to find a decent engineer who fixed your problem.

Certainly when a pressure gauge is attached to the pump you can see the pressure change as the machine goes through its start up sequence. Sorry, I do not know enough to say what is controlling these changes. - John

Gone-on-John said:

Certainly when a pressure gauge is attached to the pump you can see the pressure change as the machine goes through its start up sequence. Sorry, I do not know enough to say what is controlling these changes. - John

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Hi John. After posting this question yesterday I carried on thinking about it and I’m sure I’ve figured it. Thanks for posting your initial query and thanks for the information you’ve supplied, although this is just for these burners used and may differ from other twin pressure jets it’s taught me a lot about them, something I always wanted to achieve.

Hi, can you tell me the name of your engineer in West Somerset please