
AS-H40Y - 12kW
AS-H50Y - 15kW
AS-H60Y - 18kW
ALTO
Heat Pump installation manual
F1-F7

1
CUSTOMER NAME........................................................................
POOL DEALER..............................................................................
DATE INSTALLED..........................................................................
SERIAL NO.....................................................................................
MODEL...........................................................................................
SAFETY INSTRUCTIONS
Please read this safety instruction carefully before operation.
Heat pump must remain upright at all times.
Do not place objects on to heat pump
Do not disconnect/connect power supply during operation as this may cause serious damage.
Do not insert objects into the air inlet/air outlet grilles.
All electrical connections should be made by a qualified electrician. Do not connect heater to an electrical
supply using a 13 amp plug.
When cleaning the heater unit switch off power supply.
Do not operate electrical switches with wet hands.
Repair or relocation should be carried out by a specialist contractor.
INDEX
Page 4 ............... Installation and Siting
Page 5 ............... Plumbing
Page 9 ............... Electrical Connection & Circuit Diagram
Page 10 ............... Control Panel Functions F1-F7
Page 13 ............. Refrigerant/Flow Meter
Page 14 ............. Control Panel Error Display E1-E4
Page 15 ............. Auto Restart and Defrosting Function
Page 15 ............. FAQ
Page 16 ............. Water Chemistry / Winterising & Start-up Procedure
Page 17 ............. Warranty Policy
Page 18 ............. Heat pump Service & Breakdown
Page 19 ............. Alto Heat Pump Specification

3
HEAT PUMP- AS-H50Y (15kW) & AS-H60 (18kW)

INSTALLATION AND SITING
Prior to installing your heat pump:-
All heat pumps are factory assembled and tested prior to delivery. Please check for any external damage
especially to the evaporator fins, please diagram below. Do not be concerned about minor damage or indentations
to the fins (especially where the fan unit is mounted) as it will not affect performance. If severe damage has
occurred please contact your supplier immediately and do not attempt to install heater unit.
Siting
As the air flow is discharged from the top of the heat pump all units are designed to be installed outside. If unit is to
be installed inside the filtration/plant room adequate ducting and ventilation must be installed. Please contact your
dealer for advice.
Heater unit must be installed using plastic anti vibration pads (provided) on a solid LEVEL foundation i.e.
concrete base or paving slabs. Using the plastic pads reduces vibration noise and prevents corrosion to the base
of the heat pump. DO NOT PLACE ONTO SOFT GROUND I.E. GRASS. Please Note: the heat pump collects
condensation from the evaporator fins and will continually discharge small amounts of condensate (water) out of
the base of the unit via a drain tube. Therefore, it is recommended that the drain tube is directed to an area with
adequate drainage.
Make sure that heat pump remains free of any obstructions, foliage etc. A minimum clearance is required around
heater unit, please see drawing below. Make sure that easy access can be gained to service panel and plumbing
connections. Do not obstruct access panel with plumbing pipework.
Multiple connections- install heat pumps 500mm apart and independently protect each unit by 20amp MCB - see
also page 8, Drw.4 for plumbing detail. Make sure that heat pump grilles are not blocked by loose debris such as
leaves, grass cuttings, garden
furniture etc.
Min. 1000mm
Drain Tube
(optional)
Min. 3500mm
Min. 1000mm
Min. 800mm
Min. 500mm
4
Evaporator Fins
x 3 sides
(protected by a wire
mesh grille)
2.5mm Cable
Power Supply
(prefitted)
IF HEAT PUMP HAS BEEN PLACED ON IT’S SIDE IN TRANSIT THEN HEATER MUST BE LEFT
IN AN UPRIGHT POSITION FOR A MINIMUM PERIOD OF 24HRS PRIOR TO OPERATION
(failing the above may cause damage to the heat pump and invalidate your warranty).

5
PLUMBING
Alto heat pumps are supplied with 1.5" BSP parallel threads, male. We
strongly recommend a 1.5" female socket union is applied to
inlet/outlets for future draining and servicing of the appliance.
Alto heat pumps must be installed in the return line after the filter. If an
existing heater or back-up heater has been installed then the heat pump
should be installed between the filter and the other heater. If solar
heating has been installed, the heat pump should be installed after the solar heating system. See Drw.2 page7.
If the heat pump is to be installed at a lower level than the pool then isolation valves or non-return valves should be
installed.
Do not route any plumbing lines across heater inlet panels. All plumbing should be adequately supported.
Once all plumbing connections have been completed the filtration should be turned on and the systems tested for
leaks. A refrigerant/flow meter is located next to the control panel. Alto heat pumps will generally take the full flow
of the filtration pump. In some instances if there is too much flow (see page 12 re refrigerant/ flow meter) a by-pass
may be required. If there is insufficient flow an auxiliary booster pump may be required. Please contact your dealer
for advice.
Important - (applicable for stainless steel/copper heat exchangers) Standard unit. If your pool has an automatic
chemical dosing appliance the heat pump should be installed prior to the dosing system. See applicable drawings
(1-4) on pages 7-8.
2 x1.5” Female/Threaded
Socket Unions Required
FLOW SWITCH (Optional)
Alto heat pumps have the option of installing a flow switch. A flow switch will deactivate the heater if there is a loss
of water flow i.e. in the event that the circulation pump deprimes (no flow) the heater
will switch off.
We recommend that the heat pump should be interlock wired with the
circulation pump i.e. heat pump only functions when pool circulation pump is
running. A flow switch (provided) can also be installed as an extra precaution in
the event that there is a loss of water flow (i.e. circulation pump deprimes).
It is our recommendation that the flow switch is installed for added protection
on a pool installation that is below ground. If the heater is to be installed on an
above ground pool, the circulation pump is normally under flooded suction
therefore, heater and filtration pump could be wired together.
In the event that there is no flow ‘E3’ will be displayed on the control panel and
heater will stop functioning.
ELECTRICIAN NOTE - PLEASE CHECK CONTINUITY OF FLOW SWITCH BEFORE INSTALLING.
PLEASE ALSO SEE PAGE 15 - FILTRATION & FAQ
1 X FLOW SWITCH
1 X CRIMP -ON CONNECTIONS
1 X 1.5”- 0.75” PLN RED. BUSH
1 X 0.75” PLAIN - 0.5” FEMALE THR. RED. BUSH