Halstead Ace problems

[barnaclebill123]

Hi all, I have a problem with my Halstead ace boiler. When either CH or DHW is requested, CH or DHW demand L.E.D lights and the burners come on but after a few seconds,minutes, half hour (time varies) both the burner and demand L.E.D drop out and boiler stops, and cycle keeps repeating itself.
I have had a new fan fitted (cured problem for a bout 3 days then started again). I have had a new PSW fitted to the fan, and the venturi has been blown out but not chemicaly cleaned (again cured problem for about a day and same started again). Have noticed that when the covers are off problem seems to go away, but obviously it is only being run for a small amount of time without covers on. I am an instrument technician so understand how things work but not being corgi registered I leave the work to my plumber, but he seems a bit stumped. Any suggestions?
Thanks

 

[adlplumbing]

not much knowledge of this boiler if get no joy get your plumber to ring manufacture and ask them for some technical support

 

[zk]

get a registered gas engineer to check the flue, hoses from the fan to the air pressure switch and the aps.

 

[past3bar]

CH Thermistor

 

[barnaclebill123]

When a new pressure relief valve is fitted, does it require setting up or does it come at a set pressure?

Cheers

 

[transam]

I assume you mean the air pressure switch ? if it is an original halsead spare than it would be preset , u can get adjustable aps's , if boiler runs o.k with comb' chamber off , u have a fan , aps , or flue problem .

 

[Terrywookfit]

It's factory set to pressure stamped on head.

Check that the Venturi have not melted and distorted.