Fault Finding - Potterton Envoy System 30 Installation & Service Instructions Manual

5. Fault Finding - Page 25
Digital Display
This boiler is fitted with a single digit display which is located
in the front control box behind the hinged door.
The display on which up to 30 different characters can be
illuminated performs two functions.
1. By displaying the following characters provides the user
with a visual indication of the current boiler operating
status.
Power supply switched on but waiting for a call for
heat from secondary controls or boiler control switch
is in the '..'' position.
Boiler operating, high flow temperature selected.
2. By displaying the following characters it will assist the service engineer by working as a fault diagnosing system.
Sensor
Flow sensor
Case temperature
Dry fire
Flow sensor
Return sensor
Case sensor
Dry fire sensor
Fan speed
Shorted signal
Flame loss
Control failed
Wiring fault
Preliminary Test Diagnostics
All boilers are fully tested before leaving the factory therefore if an electrical problem is experienced it is very likely that this
is caused by faulty external wiring. If a problem exits, disconnect all site wiring from boiler. Connect a direct fused electrical
supply to boiler terminals L, Swl, N & E.
If the boiler now operates correctly the site wiring should be investigated further.
Publication No. 559787
Supplied By www.heating spares.co Tel. 0161 620 6677
Boiler operating, low flow temperature selected.
Boiler operating but up to temperature.
Boiler re-start delayed to prevent rapid cycling (Max.
delay time 5 mins).
Main burner off, pump running to transfer remaining
heat from boiler into the system.
Flashing - boiler at Lock-Out
DISPLAY NOT ILLUMINATED - all power off.
Flow or return sensor out of calibration
Flow sensor is incorrectly fitted
Temperature within boiler casing too high
Boiler has been fired without water
Sensor failed open or closed circuit
Sensor failed open or closed circuit
Sensor failed open or closed circuit
Sensor failed open or closed circuit
Fan speed incorrect
Flame signal shorted to ground
Flame loss after initial detection
Control has failed
Live on neutral connection
See chart
Check sensor
See chart
Check system
Replace sensor
Replace sensor
Replace sensor
Replace sensor
See chart
Check igniter etc
See chart
Replace control
Correct fault

Fault Finding 25