worcestor bosch 24i junior non condensing AGAIN PLEASE HELP Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[bittybunny]

. hi htg ENGINEER no fan does not run,when boiler first turned on there is no power to the fan and eventually goes to fault flashing 4 times a second,if i reset it and blow into aps fan starts straight away,there is no power to the fan when boiler first turned on and when i manually start it by blowing aps there is only 180 volts ac to it has the pcb had it? have been through fault find procedure test E and all resistance and continuity checks at st16 connector are good,with the fan connector at st1 removed and boiler reset there is no power at all on the L and N tracks ,if i either blow into the aps or momentarily make the contacts on the aps itself with multi meter on continuity ,ignition sequence starts but there is only 180 volts ac at st1 position,why isnt it sequencing when first turned on,will it be the pcb which has failed,aps switch is good,thanks rob

[htg engineer]

Yes it does look like it's the PCB at fault.

Have you tested the fan ? does it seem ok ?

Don't want to say yes replace PCB - for you to buy a new PCB to find the fan developed a fault and damaged the PCB, fitting a new PCB the same will happen. You need to establish whether the fan is ok - if unsure take it to local electronic shop to be tested.


htg

[bittybunny]

[quote="htg engineer"]Yes it does look like it's the PCB at fault.

Have you tested the fan ? does it seem ok ?

Don't want to say yes replace PCB - for you to buy a new PCB to find the fan developed a fault and damaged the PCB, fitting a new PCB the same will happen. You need to establish whether the fan is ok - if unsure take it to local electronic shop to be tested.


htg[/quote] hi htg engineer fan seems okay no play in bearings nice and free etc,what electrical values do i need to look for with my multi,does not give them in the manual thanks rob

[bittybunny]

[quote="htg engineer"]Yes it does look like it's the PCB at fault.

Have you tested the fan ? does it seem ok ?

Don't want to say yes replace PCB - for you to buy a new PCB to find the fan developed a fault and damaged the PCB, fitting a new PCB the same will happen. You need to establish whether the fan is ok - if unsure take it to local electronic shop to be tested.


htg[ hi htg engineer fan bearings ok,not stiff spins nice and free,done resistance checks at fan connector when taken off the board as advised in manual 2 days ago and are within spec black cable to white cable approx 135 ohms can be between 75 and 175,black cable to red cable approx 60 ohms can be between 30 and 90 ohms,next check after that is check across st1 fan connector pins on the board live and neutral tracks for 230 volts on start up and it is 0 volts so points straight to pcb fault,more so when with the st1 fan connector removed from the board and blow down the aps tube to make the aps click and continue ignition sequence after the pump has turned on there is only 180 volts at the st1 fan connector position live and neutral on the pcb ,thanks rob

[htg engineer]

Well yes, i'd be happy replacing PCB.

htg

[bittybunny]

[quote="htg engineer"]Well yes, i'd be happy replacing PCB.

htg[/quote] thanks htg you is a star as im sure you been told many times,rob