Faulty Valiant Turbomax plus 837e

[Poynton Plumber]

i'm having problems with my Valiant boiler. it stopped working 4 week ago.
we have a sevice/repair contract and had an enginner come out, who diagnosed it as a faulty circuit board. it took over a week for a replacement with a different engineer, who claimed he didn't know anything about the job, but replaced the circuit board. he couldn't get it to work, and spent 15 mins on the phone being talked thru several steps, only to be told that the new board was faulty. another week went by and the engineer turned up today with a new borad, again no immediate joy and a further 15 mins on the phone, to be told it must be a faulty fan.
i have had a look thru the manual and it says that you may have to set it for the correct type of gas, which i have tried, but buttons that cycle thru the setup sequences are unresponsive.
does anybody have any suggestions as to what i might try next.
are there any manual switches on the board itself that have to be set depending on the type of gas etc.
i am a plumber, but have little experience with the boiler side of things as i dont have my gas qualis yet.
Help

Steve
p.s sorry for the epic tale.

 

[NellyC]

i'm having problems with my Valiant boiler. it stopped working 4 week ago.
we have a sevice/repair contract and had an enginner come out, who diagnosed it as a faulty circuit board. it took over a week for a replacement with a different engineer, who claimed he didn't know anything about the job, but replaced the circuit board. he couldn't get it to work, and spent 15 mins on the phone being talked thru several steps, only to be told that the new board was faulty. another week went by and the engineer turned up today with a new borad, again no immediate joy and a further 15 mins on the phone, to be told it must be a faulty fan.
i have had a look thru the manual and it says that you may have to set it for the correct type of gas, which i have tried, but buttons that cycle thru the setup sequences are unresponsive.
does anybody have any suggestions as to what i might try next.
are there any manual switches on the board itself that have to be set depending on the type of gas etc.
i am a plumber, but have little experience with the boiler side of things as i dont have my gas qualis yet.
Help

Steve
p.s sorry for the epic tale.

what was the initial fault? any codes? circuit board is always the easy way out of fault finding. Did any1 put a multimeter on the boiler😱

 

[wnjswozo]

pump pressue switch,you need multimeter,
combis work in sequence ,pump fan,aps,gas
basic continuity test first

 

[Poynton Plumber]

NellyC
cant remember the fault code, but the boiler just wouldn't fire when either hot water or heating calles.
the engineer put a test meter on the board and said their was no power supply to the fan