boiler ignition sequence

[bob the plumber]

hello, doing my ACS at the moment for the first time, is there anyone here who can tell me the sequence in which contols are activated on say a combi with a hot tap that has been turned on. i have a good idea but id like to know for sure. hot tap on, dhw flow switch, fan, pump, air pressure switch ...

any help would be much appreciated

 

[Billy Bob Bob]

demand,proving ignition,gas,detection
demand tap open,dhw switch makes,diverter moves,fan on proving aps satisfied,ignition,gas gasvalve opens,detection detection electrode tells the pcb burner has cross lit sequence complete

 

[villa_tom]

demand,proving ignition,gas,detection
demand tap open,dhw switch makes,diverter moves,fan on proving aps satisfied,ignition,gas gasvalve opens,detection detection electrode tells the pcb burner has cross lit sequence complete

Sounds like you've swollowed a boiler manual

 

[Billy Bob Bob]

yea i know rennies dont cut it indigestions killing me

 

[obseen16]

Gasman what happened to the pump?

 

[Billy Bob Bob]

Gasman what happened to the pump?

then it kettles its head off because the pump was knackerd ,high limit stat kicked in and its in flame failure

 

[Dotty]

There you go! Igbition sequence, failure and fault finding in one easy breath.

Don't come any better than that!