Fault Finding - Warmworld FFC 30/60 Installation & Service Instructions Manual

Fault Finding

The electrical sequence in the boiler is very straightforward and faults can easily be tracked down if this simple
sequence is followed.
System Controls - - - - Flue Stat - - - - Overheat Stat - - - - Pressure Switch - - - - Control Board - - - - Ignition
The lamps on the front panel indicate several of the stages in the ignition sequence.
Firstly a Permanent live has to be connected to the L terminal then the power (
When the system controls and the programmer are calling for heat, power is fed to the boiler initiating the
following sequence.
A call for heat powers the Ls terminal and the running (
Provided the Flue Stat, Overheat Stat and boiler are cold, the fan starts up. The pressure switch detects the
correct airflow and that the condensate drain is not blocked then, switches over. This is indicated by the
fan ( ) lamp illuminating.
The pilot ( ) lamp illuminates, the pilot gas valve opens and the Control Board provides a spark at the pilot
electrode. (If the L and N supply are reversed the boiler will not progress beyond pilot ignition. This is indicated
by the phase reversed neon behind the knob lighting.) The pilot flame is detected and the control board stops
sparking and then energises the main gas valve and the burner (
The pilot flame lights the burner, and it stays alight until turned off by the control thermostat, system controls, or
in the case of a fault condition a safety thermostat.
The flue thermostat will trip if the flue exceeds a pre-set temperature. The overheat thermostat will trip if the
water flow rate is insufficient, both are indicated by the lockout lamp (
NOTE:
The boiler has a built-in delay timer. It is indicated by the running (
For testing, switching the Mains Supply off for a few seconds, then back on again will reset the delay.
WARNING: BEFORE COMMENCING OR COMPLETING ANY ELECTRICAL WORK ON
THE APPLIANCE, IT IS RECOMMENDED THAT THE BASIC SAFETY CHECKS FOR
EARTH CONTINUITY, SHORT CIRCUIT, POLARITY AND RESISTANCE TO EARTH ARE
MADE. ALL WORK CARRIED OUT SHOULD FOLLOW GUIDELINES LAID DOWN BY
THE I.E.E.
Fault Diagnosis
The fault Diagnosis chart shows the normal and fault sequences for the boiler indicator lamps.
To diagnose a fault, use the following procedure.
Turn off the system Mains supply.
Set all thermostats and timers to a call for heat position.
Turn on the system Mains supply and watch the boiler indicator lamps.
Compare the lamps with the diagnosis chart opposite to determine the fault and cause.
Condensing Boiler
) and pump (
) lamp is illuminated.
) illuminating.
18
) lamp lights.
) lamps light.
) lamp flashing.
10/04/00