Heating And Hot Water - Bosch Worcester Greenstar Danesmoor External Regular ErP+ 12/18 Installation, Commissioning And Servicing Instruction Manual

Fault finding and diagnosis
8.2

Heating and hot water

These fault finding charts are provided to assist competent and suitably qualified engineers to locate and rectify faults. Whilst every effort has been
taken to ensure the information given is correct and complete we cannot guarantee that every eventuality has been covered.
Worcester, Bosch Group cannot be held responsible for costs incurred by persons not deemed to be competent.
Measure all 230V tests between Neutral (N) and the pin, wire or terminal specified.
Set the service switch to
Boiler mode
No
Is the service switch set to
Boiler mode?
Yes
No demand to the boiler.
Check external supply and
wiring. Rectify the fault.
40
Start
No heating/hot water
Is the demand light
No Yes
illuminated?
Is there 230V on pin 2 of
connection on the burner
Locate fault between the
Greenstar Danesmoor External
UNDER NO
CIRCUMSTANCES MUST
AN APPLIANCE BE LEFT
OPERATING WITH ANY
CONTROL LINKED OUT OR
OVER RIDDEN.
Follow the control box
Is the burner lockout
Yes
fault finding chart to
light illuminated?
locate fault.
No
Lack of system water circulation.
Yes
Is the boiler hot? Check the pump, valves and system.
No
Is the flue or boiler Reset the thermostat and investigate
Yes
overheat thermostat cause of overheat. If the thermostat
tripped out? will not reset replace the thermostat.
No
Replace the control
No
the control thermostat?
thermostat.
(the brown wire)
Yes
Is there 230V on the
Replace the boiler
No
orange wire to the flue
overheat thermostat.
overheat thermostat?
Yes
Is there 230V on the
Replace the flue
No
brown wire from the flue
overheat thermostat.
overheat thermostat?
Yes
Is there 230V on pin 2
Replace the high
No
(brown wire) on the
limit thermostat.
burner socket?
Yes
Is there 230V on the L
Replace the burner
Yes
control box.
control box?
No
control thermostat and
the burner. Repair
fault/replace lead.
ErP+ and External System
Rectify the fault.
6720809437-44.1Wo
ErP+ 6720821725 (2018/04)