there are two main problems that happen with the 80e 1/ the diverter valve and 2/ the gas pcb , your problem seems to be the diverter valve to check this remove the front cover in the boiler you will see a brass valve body the end having a 3" dia flange the main body part has 5 pipe connections onit the flange end has a plastic box on it which has a micro switch in it operated by a 1/8" dia shaft by the diaphragam inside the flanged diverter valve ,to check the action of this get some one to open the hot tap and you should just here a click of the switch if you turn the box you will see the shaft move out to strike the switch, if this does not happen then you need to replace the diaphragam,this is a common thing and has to be be replaced about every 5 years may be,be very careful turning the box as the micro switch has open 240 volt connections at the back. the other fault is the gas valve pcb which has to be taken out to repair this problem and needs a more detailed explanation,try the diverter problem first ask again if needs be. ps when working on the boiler turn off the power and gas [DO NOT MESS WITH THE GAS ] BANG!.
BOBBY ROB, January 2007
