Commissioning – Grant Products HPAW155 User Manual
Return water temperature to start electrical heater
Desired Return water temperature setting
SET TO 60˚C
Coil temperature point to start defrosting
Coil temperature point to stop defrosting
Max time for defrosting
Restart after power failure
0/1 0=NO, 1=Yes
EEV manual / auto control
Water pump working mode, 0= Continuous, 1=Normal
Fan motor working mode
0= daytime working mode, 1=night time working mode
Manual control paces of EEV
Temperature point to start electrical element (ambient)
-5˚C to +5˚C
Return gas temp.
Tank water temp.
EEV actual open paces
Take a note of these settings and write them in the Commissioning sheet in section 16.
IMPORTANT - Do not adjust Factory Set parameters unless instructed by Grant UK to do so.
Information about the ATC
Fan Motor Operation
1. Normal (night time) working mode -
when Parameter A set to 1. Refer to
Table of ATC Parameters above
a) When in heating mode (CH or DHW),
fan motor starts up to 60 seconds
before compressor starts.
b) When ambient temperature is higher
than 25°C, fan motor switches to low
fan. When ambient temperature is
lower than 23°C, fan motor switches
to high fan.
c) During period 20:00 to 8:00 (next
morning), fan motor switches to low
speed (time according to the ATC
d) During all other periods, fan motor
works at full speed according to
e) During defrosting, fan motor works
according to defrost mode
2. Normal (daytime) working mode -
when Parameter A set to 0
Fan operates as described above for
‘night time’ operation but with NO Low
speed fan operation during period
20:00 to 8:00 (next morning).
Electric Immersion Heater and
Trace Heater Operation
Started by ambient temperature -
Parameter d Setting
Refer to Table of ATC Parameters
Regardless of whether the ATC is in
‘Standby’ or ‘Auto’ mode, when either:
a) Return water temperature is 2°C
lower than the parameter d
temperature setting (adjustable
between -10°C to +5°C with default
setting 3°C), OR
b) Ambient temperature is at parameter
d temperature setting
BOTH the Electric immersion backup
heater and Trace Heater (in the base
tray) will be energised.
Both will remain energised until either:
a) the Return water temperature has
reached set temperature (55°C) OR
b) the ambient temperature is higher
than the parameter d temperature
setting If the Return water temperature
rise is less than 1°C in a 20 minute
period when the heat pump is
operating – parameter 0 set to 1°C
(adjustable between 0°C and 30°C with
default setting of 2°C) the Electric
Immersion backup heater (and trace
heater) will be energised to increase the
heat output of the heat pump.
The Electric Immersion heater (and
Trace heater) will be switched off when
the Return water temperature reaches
In a Bivalent system the electric immersion
element is disconnected and the
switched live for the backup boiler is
taken from the immersion element live
terminal – refer to Figures 8-7 and 8-11.
Thus the backup boiler will be
energised under the same parameters
as given above for the electric
immersion element and trace heater.
In all conditions, the circulating pump
will operate when the ambient
temperature falls below 5°C. This is part
of the frost protection and cannot be
adjusted by the user.
1. When ambient air temperature is
less than 5°C, the circulating pump
will start. The pump will stop when
air temperature is above 6°C.
2. When ambient air temperature is
less than 0°C AND the return water
temperature is less than 5°C, the
heat pump will start. The Heat pump
will stop when return water
temperature is above 8°C.