Halstead Quattro Gold intermittent hot water

[Mike Rabbit]

Hi peeps. One of my customers has a quattro gold and complains of intermittent hot water. I was lucky enough to be present when the problem manifested itself. It seems that 80% of the time the burner pressure is correct but occasionally it stays on ignition rate or minimum modulation rate of about 3 mbar.?????
Any ideas?? Am thinking circuit board but which one??

Any input much appreciated. Mike.

 

[dancinplumba]

are you gsr ?

 

[Mike Rabbit]

Hi. I have city and guilds in gas fitting from a british gas apprenticeship, I was field service engineer for Vaillant for 21 years, and hold all domestic NACS certificates valid until June this year. But registered NO!