9
>
check there is 230 V AC :
at the supply
at the appliance plug
>
then check : the connections to the ignition PCB
the fuse on the PCB
the thermistor connections
the flow sensor connections
>
check that the gas supply is turned on
>
check that there is sufficient gas pressure to the
heater
>
check that the gas supply is turned on
>
check that there is suffient gas pressure to the heater
>
change gas valve
>
change main PCB
>
Correct live and neutral connections to the heater
>
change ignition PCB
>
incorrectly fitted or obstructed flue
>
check connections to the air pressure switch and
that the tubes are not blocked or spilt :
>
check air pressure switch : change if necessary
>
check electrode lead : change if necessary
>
check flame sense lead : change if necessary
>
change ignition PCB
>
change main PCB
no electrical supply
no gas flow
gas valve
reversed
live and neutral
flue system
ignition system
the water-heater will not run but
the safety indicator light is not lit
the water-heater will not run =
safety disconnection
the spark train does not light the
burner = safety disconnection
The burner lights for less than 10
seconds, then goes out
there is no spark train then the fan
runs = safety disconnection
fault
cause >
remedy
>
change temperature sensor
>
change main PCB
>
heat exchanger blocked : descale or replace
>
change temperature sensor
>
change main PCB
>
change gas valve
electrical circuit
water circuit
electrical circuit
water too hot = safety discon-
nection
water is not hot enough (maxi-
mum temp 50°C at 5 l/min con-
trol at max)
FAULT FINDING
