Vokera Excell 80 SP - Pilot light on but gas does not ignite - no hot water?

more than likely a diaphragm fault, on the excell diaphragm pushes pin out moving a lever arm which makes the microswitch, as diaphragm weakens/holes/splits arm doesn't move as far and starts struggling to reach microswitch, its like a pivot. thats where i would look first off. cheapish part, bit fiddly

x
September 2009

the way this boiler works is; if there is a demand then the pump will run, the flow switch diaphragm will move to make a switch to prove the pump is running, it should then send power to the fan so it runs at full speed, the air pressure switch should then make and send power to the gas valve which should in turn open and allow the main burner to light. at what point is it failing? i.e can you hear the fan running? if so shortly after the fan runs can you hear a small click which is the air pressure switch making?

You'll need to get a qualified engineer to repair it whatever the fault but it's best if you have a rough idea what it is likely to be.

Ian
September 2009

pilot light on and pump is working but will notfire up

gerry hill
September 2009