Grant Products HPAW155 - Manual (Page 40)

36
Fault Finding
13 Fault Finding
Is there
power to the
heat pump?
STOP! Call the
helpline for
assistance
Is ATC in the
automatic
position?
Is heat pump
working?
Press ‘M’ on the ATC
until the sun symbol
is illuminated
Is the BTC showing
any demand or
WWSD?
Check 24Vac to pins
12 & 24 on BTC is
present?
The heat pump
appears to be
working correctly
Check pressure gauge
on side of heat pump
- see note 5
Bleed air from
system - see note 7
Refrigerant low
- call helpline
Check capacitors
and replace if
necessary CAUTION
- see note 6
Has heat pump
tripped on high or
low pressure switch?
Is there power to the
component leaving
the PCB?
Can this fault code
be repaired?
Does BTC show
any fault code?
High pressure
switch?
Low pressure
switch?
Trace fault on Heat
Pump See note 4
Can this fault code
be repaired?
Is the power at
the component?
Does ATC show
any fault code?
Is the circulating
pump running?
Is the fan
running?
Is the compressor
running?
Is there a demand from
the heating system?
Is heat pump in
defrost mode
Fault in system
wiring - see note 2
Normal Condition
See note 3
Is there continuity
between terminal 1 &
2 and 1 & 3 at Heat
Pump control panel?
see note 1
Is the external
isolator turner on?
Turn on - Is
system working?
Problem solved!
Reset MCB
or RCD
Has MCB or
RCD tripped?
Does heat pump
run without
tripping?
Switch external
isolator ‘OFF’
Reset MCB
or RCD
Does MCB
or RCD trip?
Seek help from
qualified electrician
Replace
component
Replace PCB
Replace BTC
No
Yes
Yes
Ye
s
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes Yes
Yes
Yes
Yes
Yes
Yes No
No
No
No
WWSD
No
No
No
No
No
No
No
No
No No
Not sure
BEGIN HERE
Yes
Yes
13.1 Fault Finding Flow Chart