Have to replace a PCB on an Ariston SX20. It looks relatively straight forward - (take out the pcb disconnect the wires then replace with new) but wanted to check if any detailed knowledge is required or is it as simple as it appeared. I'm presuming that the wires just push into the designated slots on the unit and that no vast electrical knowledge is required. (aside from turning off the mains) Also anyone got any ideas as how much labour should cost to undertake this job in London should I choose that option.

K Adair, January 2007

Many thanks for your quick reply. It is the SX20 MFFI model but will prob leave it to the pros in case I make a total hash of it :-) Do you know off hand how long replacing it and doing all the necessary checks should take? I'm worried I'll get taken for a mug

Katrina Adair, January 2007

The Ariston SX20 is not the exact model. It will be either the SX20MFF or the SX20MFFi. These boilers use totally different pcb's. With the SX20MFF, two of the plug in connectors are the same size, and can be crossed over quite easily. Make sure they go on the correct terminals.
The SX20MFFi has alternative sized multiplugs that cannot be crossed, but care should be taken with the green external controls connection as it is possible to miss the connection pins and simply wedge it by the side instead.
As for tools, a multimeter is required to ensure that no electricity is present when you change the part, and that you have not created a live/neutral to earth problem. Also a manometer (commonly called a U guage) will be required to set the heating output rate via the potentiometer on the board.
With regrad to costs in London I'm afraid I can't help you as I'm in the Midlands

David Hickey, January 2007