I too have the problem of SE flashing intermitently on the Worcester Bosch 35CDi boiler. I would also like to know what SE represents.

Paul Scarbro, December 2007

it’s been known for the code to show up too early in some circumstances. This indicates that the burner inside the boiler has been running longer than expected, at lower output and higher efficiency.

If that happens then be sure to call an engineer out.

https://abgoheatingspares.home.blog/2019/03/07/how-to-diagnose-the-se-code-on-your-boiler/

Jake, March 2019

water goes hot and cold when using shower

peter, October 2018

Thes instructions couldnt be easier, great that all works fine.

Thanks

Damage3245, November 2016

Thank you so much for your advice and help we
Whoever you are? It did the job and saved me 45 pounds to get I reset. Thanks once again.

Minesh chauhan, January 2014

how do i restart the pilot if its gone out

david smith, September 2012

What does the 'SE' code flashing up on my Greenstar CDI boiler mean?
This is a feature of certain CDi boilers. The code is activated after 2,324 of burner hours and serves as a reminder that the boiler requires a service every 12 months. The code can be cleared by following these instructions:

Hold down the spanner button until illuminated and release
Push the eco button until “5.a” is displayed
Push and release the chimney sweep button to display “00”
Hold down the chimney sweep button until [ ] is displayed, and release
Press spanner button once

IO, December 2007