what is the f4 code on a ultracom 30cxi?

f4 code. "flame goes out when lit".

lots of causes for this fault download the manual from glow worm at this address

http://www.glow-worm.co.uk/products/pdf/current/Ultracom_cx_installation_manual.pdf

and have a look, gives all fault codes, most of the faults listed will need a plumber to correct.

Denis
December 2009