ariston A23 MFFI

[monbello]

I have an ariston a23 mffi which will not fire up normally either on hot water or central heating. Ican get it to fire up by pressing the reset button on the extreme lh side ,then it runs for 8 to 10 seconds then cuts out. if i press the reset button again it will fire up again ,cutting out again.Is this cutting out on overtemp due to low water flow? or something else? in any case please help point me in the right direction. THANKS

 

[ScottishGasMan]

if it cuts out after 10 sec and you push reset straight away will it come straight back on? if so I doubt its over heating as usualy a boiler will need time to cool a little first before itll come back on.

If this is the case it may be a flame sensing problem etc, i dont have instructions for that boiler handy so dont know if that button is purly over heat or ignition aswell.

 

[monbello]

thanks for your helpfull reply, i have replaced the flame sensor to no avail, also when it fires up the ignition spark keeps on going (not noticed before, now cover removed)presumably because,as you say it is not detecting the flame.all other things checked ok by my corgi regd nephew,he can only say its the pcb thats faulty order a new one 90quid!! I can repair it(electonics bod) but a circuit diag would be helpfull.anybody got one? or anybody know the fault staight off? most greatfull for any help. THANKS

 

[Agile]

You dont get circuit diagrams for boilers!

Check the 1 meg or similar in series with flame detection electrode. They often go o/c.

Tony