Symptoms-
When CH switched on (manual or timer) lots of clicking noise from pump area / bottom of unit. No ignition.
If HW on whilst in above condition clicking stops but returns as soon as HW tap closed - Ignites for HW, but switches off when HW tap closed.

Martin, December 2008

Many thanks 'Al' - will oder and try

Martin, January 2009

On Pcb marked RL1(Relay) needs changing.it is clear body sealed unit.
Relay1( one) clicking,Not expansive
part no is .... OMRN G2 R2 24v dc .... (Relay).
search web From £5 to 25 Part price .
soldering is easy if u cando yourself,It cost me 3.50.incp&p.
Pcb is located at bottom near controls,screws,wire connections to dismantle.use commonsense.

al, December 2008