IDEAL Response FF80, Installation And Servicing, Page: 50 / 64

50 Response FF80
- Installation
Note 1 . At the end of a call for heat by the room thermostat / time control, a 2 minute pump overrun period occurs. During this
time the boiler will not restart for CH
even if the controls are calling for heat . This is done to prevent uneconomical
'short cycling.' This period can be curtailed by running a hot tap for a few seconds.
Note 2. When panels are removed for service, live parts are exposed so caution should be exercised when fault-finding.
YES
YES
NO
YES
Unplug the lead from the CH sensor
and connect temporarily to a
replacement sensor, if available.
(Alternatively, see footnote.)
Does the boiler now operate ?
Fit new CH
sensor
YES
NO
Change
harness 100.
Does boiler
now operate ?
NO
Check for air
locks and
closed valves
preventing
proper
circulation
YES
NO
Is there power at the
pump itself ?
Is the boiler
hot ?
Is the pump
running ?
NO
NO
NO
Is there power to
the pump at the
connector on
PCB 38 ?
YES
Check the CH sensor and panel
control and/or the wires connecting
them to the PCB.
Are the wires and connections OK ?
YES
Is the CH light on PCB 38 flashing ?
Check
lead to
pump
Replace
cap
Switch off
and change
pump
YES
Is the HW light lit
on PCB 38 ?
If the boiler has been unused with
mains off, the pump may be stuck.
Remove screw cap on the pump
head and turn the shaft with a
screwdriver until free.
Does the pump now run ?
NO YES
NO
Check all connections to PCB 38.
Check for moisture on PCB 38.
If no fault found check PCB 38 by substitution.
Reconnect the
flow switch
Change faulty
flow switch
YES
NO
Check all connections to PCB 38.
Check for moisture on PCB 38.
If no fault found check PCB 38 by
substitution.
Check that there is no flow,
e.g. to taps or automatic
washing machines.
If you are sure there is no HW
being used, disconnect the
lead to the flow switch at PCB
38.
Does boiler now give CH ?
If no fault
found
Check heating
controls are
all calling for
heat and are
correctly
wired.
FAULT FINDING
CHECKING CH AND HW THERMISTOR SENSORS
The sensors can be checked by measuring their
resistance, using a suitable multimeter connected
across the sensors' terminal pins.
At room temperature expect 9,000 to 11,000 Ohms
At 60°C. expect 2,000 to 2,500 Ohms
At 85°C. expect 1,000 to 1,500 Ohms
80 HW but no CH
F
AUL
T FINDING