Rayburn 499kb lockout problem

[Muttley]

I have a fault on my Rayburn 499KB. The boiler side fires up fine when cold. Once its hot, or oven hot, it will not fire & goes to lockout.
Cooker side is working fine. Has Ecoflam twin burners.
I have had the burner out & replaced damaged PEC, leaking capacitor and both burner nozzles. Have also swapped control boxes.
None of which worked.
Any ideas what fault may be before I get engineer in?

 

[Timmy D]

This is probably not want you want to hear but you need to get an engineer in.

By changing the nozzles you’ve altered the combustion characteristics.

It’s likely not burning correctly and creating additional soot/CO. The soot will block the heat exchanger making everything worst.

Oil boilers should be serviced/new filters/nozzles/hoses every year. This is important, more so than with gas as oil is much dirtier.

Pump pressure needs to be checked, soot levels with soot pump and then flue gases.

I spent Thursday cleaning this.

 

[Muttley]

Only changed nozzles today. Had the lockout problem for 3 weeks, so I have not caused it by changing nozzles.

 

[Timmy D]

Only changed nozzles today. Had the lockout problem for 3 weeks, so I have not caused it by changing nozzles.

I know that. Just pointing out that you shouldn’t be changing boiler parts, especially combustion without the tools to test your work and the knowledge/qualifications to understand the risks/impact of changing said parts.

Unfortunately you won’t get the advice you require from this site without first proving your qualifications.

Like I said, it’s not want you want to hear but it’s like this to protect people. You may be quite competent but we, as advice givers can not determine that.

Get the engineer in, save yourself headache and money by not throwing random parts at the boiler.

 

[SimonG]

Only changed nozzles today. Had the lockout problem for 3 weeks, so I have not caused it by changing nozzles.

No but without the correct equipment to check the combustion after a nozzle change how do you know you dont have further issues.

It's an easy fix for an engineer that would cost a fraction of your spend on unnecessary bits you've already thrown at it and the cause is actually outlined in your first paragraph of your original post.

At the end of the day it's a combustion appliance that shouldn't be played with, without the necessary tools, experience and competence.

Always a more expensive fix when the customers had a fiddle.