Potterton Performa 28i Installation And Servicing Instructions page 43

Fault Finding Solutions
A
Is there 230V at:
1. Main terminals L and N
2.
Main terminal fuse
3. Selector terminals a & b
and a & 3. PCB - A4
connector terminals 4 & 5
B
Is there 230V at:
YES
1. Pump
2.
PCB - A4 connector terminals
YES
Change pump supply cable
C
1. CH system pressure 0.5 to 1.5 bar
2.
Check automatic air vent is
open
3. Primary flow valve diaphragm damaged
D
1.
Continuity across flow
microswitch and PCB - A5
connector terminals 7 & 8
2.
Temperature sensor faulty.
Cold resistance approx. 11 kΩ
(resistance reduces with increase in temp.)
3.
Fan connections correct at fan.
PCB - A2 connector 230V
across terminals 5 & 7
NO
YES
NO
If pump jammed, release
NO
NO
NO
YES
NO
NO
YES
NO
Check electrical supply
Replace fuse
Check wiring
Replace selector
NO
Replace pump
Replace main PCB
Re-pressurise system
Open the automatic air vent
Replace diaphragm
Flow valve rod obstructed - clean, reset
Replace microswitch
YES
Replace sensor
Fan jammed or faulty winding
Replace main PCB
14.0 Fault Finding
NO
neon
illuminated
YES
Replace fan
Replace main PCB
43