Isar/Icos test procedure before PCB replacement

View previous topic View next topic Go down

Isar/Icos test procedure before PCB replacement

Post  Rich S on Sun Nov 07, 2010 9:09 am

Below is a procedure for testing the components on the Ideal Isar/Icos which are most likely to cause damage to the PCB. It would be advisable to follow this procedure before replacing the PCB to check if faulty components are the cause of the PCB failure.



FAN

Remove the connectors from the PCB and fan.
Using a multimeter on Ohms test across the two outer spade connectors you should have a resistance of 115ohms +/-10%. Any reading other than this the fan could be blowing the board, and will require replacement.


FAN HARNESS

Remove connectors from the PCB and fan.
Using a mutimeter on buzz setting
At the fan connector test from for cross continuity on all wires from right to left testing each wire to the next wire. Any buzz will indicate the harness is damaged and will require replacement.


GAS VALVE

Remove molex connector from the gas valve.
Test the resistance across the two pins you should have a resistance of 4k ohms +/- 10%.


PUMP

Remove the pump connector from the PCB
Test the resistance across the pink and brown wires you should get a resistance of around 180 ohms.


WATER DAMMAGE


Water leaking from the primary flue seal is another cause of PCB failure. Water drips from the seal which is located on the top right of the heat exchanger where the flue manifold connects, you will notice water staining down the heat exchanger.

With the boiler in operation you will see water dripping through the grommet just above user control PCB connection on the main board, it is this moisture in the harness that can cause PCB failure.

Rich S
Admin

Posts : 17
Join date : 2009-11-19

View user profile http://npht.forumotion.net

Back to top Go down

View previous topic View next topic Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum