Bosch Worcester Danesmoor Utility Regular ErP+ 12/18 Installation, Commissioning And Servicing Instruction Manual page 54

Fault finding and diagnosis
Line
5 Burner does not fire, burner locks out after 25 seconds from motor start?
5a Burner fires when the photo cell is covered?
Photo cell voltage ≥ 3.8V in the dark and
5b
approximately 0V in the light?
6 Pump washing pressure 1 to 2 bar?
6a Pump pressure more than 6 bar?
6b Check oil supply to the pump, if oil supply is OK
6c Drive coupling broken?
7 Ignition spark present?
7a Are ignition leads and electrodes OK and set correctly?
8 Solenoid coil releases working pressure?
8a Does burner light or green 0.5 seconds ON/red 0.5 seconds ON
before lockout?
8b Contaminated fuel filters?
8c Coil lead OK
Solenoid coil resistance 90 to 110 Ω
8d
8e After 15 seconds from motor start, 25 to 30 Volts d.c. to solenoid
coil? (coil connected)
9 Air set correctly?
10 Does the burner light?
Flue damper fitted? (if required)
10a Is the nozzle atomising the fuel?
10b Nozzle new?
10c Check oil pipe from pump to nozzle holder
11 Combustion head set correctly?
11a Flame goes out then re-lights
11b Boiler or flue blocked
11c If balanced flue, remove the snorkel and test - now OK?
11d Balanced flues can recirculate gases causing recycling
Photo cell voltage ≥ 3.8V in the dark and
11e
approximately 0V in the light?
Table 14
54
Check
Yes Go to line 5a
No Go to line 6
Yes Remove extraneous light
No Go to line 5b
Yes Replace the control board
No Replace the photo cell
Yes Go to line 7
No Go to line 6a
Yes Replace oil pump
No Go to line 6b
Go to line 6c
Yes Replace drive coupling
No Replace oil pump
Yes Go to line 8
No Go to line 7a
Yes Replace control box
No Replace/reset electrodes/ignition leads
Yes Go to line 9
No Go to line 8a
Yes Go to line 5a
No Go to line 8b
Yes Clean/Replace filters
No Go to line 8c
Yes Go to line 8d
No Replace solenoid coil lead
Yes Go to line 8e
No Replace solenoid coil
Yes Replace oil pump
No Replace control box
Yes Go to line 10
No Adjust combustion air settings
Yes Go to line 11
No Go to line 10a
Yes Go to line 11
No Go to line 10b
Yes Go to line 10c
No Replace nozzle
Clean/ replace pump and fuel line filters
Yes Go to line 11a
No Reset combustion head
Yes Go to line 11c
No Go to line 11b
Yes Clear blockage
No Go to line 11c
Yes Go to line 11d
No Go to line 11e
Check the flue position and seals
Yes Replace the control box
No Replace photocell
Greenstar Danesmoor Utility ErP+ and Utility System
Action
ErP+ - 6 720 821 720 (2018/04)