Bill Johnson – OMNIE Underfloor Heating, Heat Pumps & Ventilation

Alpha Innotec HMD1 Hydraulic Module Install Guide

Fitting the HMD1 to the Wall

First locate the Operating Manual for the HMD1 /E as this will be your guide. The following information should be read in conjunction with the manual; it is not instead of it,

Hydraulic Module HMD1

The Hydraulic Module contains most of the components necessary to make the heating system work;

  • Safety Set: – Pressure Relief Valve, Pressure Gauge, Auto Vent
  • 12ltr Expansion Tank
  • Circulating Pump 25/80
  • Flow Sensor
  • Microprocessor Control System with temperature inputs and 230V outputs
  • Isolating Valves with fill/purge point and vent
  • Insulated Enclosure

The HMD1 includes the wall mounting fixings with nuts and washers and the outdoor temperature sensor.

Decide where the HMD1 unit will be located in the building; as close to the LWD outside as possible is best. Try to keep the HMD1, the Buffer Tank and the DHW cylinder close together as it helps with operation and maintenance. Leave enough space on the right of the unit for access to the electrical terminals and for the cable entry.

HMD1 Install Plan
Install plan for the HMD1

Remove the unit from the box and place in a safe place. The drilling template is behind the HMD1 unit, take it and use it to mark the holes in the wall for the fixing studs. Use a Φ12mm drill to make the holes in the wall. Insert the plastic wall plugs supplied with the unit then screw in the three mounting studs.
Remove the cover from the HMD1 unit and place somewhere safe. Hang the HMD1 unit on the studs, fit the washers and the M10 nuts and tighten moderately being careful not to crush the casing.
Now fit the safety set on the top of the HMD1 unit. Use a thread sealant on the connection; a semi setting anaerobic type is best. Do not use PTFE or air setting sealants as these do not work with antifreeze in the water.
Fit the Isolating valves using the fibre washers supplied, note; the filling/purging valve is on the left.
The Return Temperature Sensor is tucked away inside the unit behind the electrical box. When the pipework has been installed remove the sensor and strap it to the common return pipe using the fitting kit included (stainless cover, cable ties and conducting paste). Make sure all the pipework is well lagged especially the sensor as this can be affected by ambient temperature.

Electrical Wiring

The cables all pass through the rubber cable glands provided on the right hands side of the unit. Pierce the rubber with a screwdriver and push the cables through. Note that the unit is not designed for SWA glands, if SWA cable is used it will be necessary to fit an adaptable box next to the unit to take the gland then run a length of flex into the HMD1. The largest cable entering the HMD1 should be no greater than 4mm² for the 6kW heater.

Connect the three power supplies to the HMD1 terminal blocks; Compressor and Heater at X7 and the Controls at X10. The details are shown on the Overview drawing below.

Wiring Overview for Packs 10 & 11

Connect the cables from the LWD unit to the terminal blocks in the HMD1; Compressor to X10, the Controls to X7 and the LIN cable to the centre connector on the Control Interface (the green plug). Clip the cable with the cable clamps provided, the LIN cable clips to the spring clip on the metal chassis. Check with the Terminal Diagram in the Operating Manual.

Pack 10 & 11 Wiring Diagram JPG
Pack 10 & 11 Wiring Diagram


Wire the DHW Diverter Valve USV1″ into the HMD terminal X3. The Live (brown) and Neutral (blue) are wired into X10 and the switched live (black) is connected to BUP on X3

Terminal X3
Luxtronic Terminal X3

If a secondary circulation pump is to be used for the DHW the live should be connected to ZIP and neutral to X7. In a standard installation the remaining terminals are not used.

The outdoor Temperature Sensor (TA) and DHW temperature sensor (TBW) must be connected to X4.

Terminal X4 Temp Sensors
Luxtronic 2.0/2.1 Terminal X4
  • Outdoor Temperature – TA- GND
  • DHW Temperature – TBW – GND

The remaining inputs are not used on a standard system.


Internet Connection

To enable the remote maintenance feature the controller must be connected to the internet via a Broadband Router. Plug a Cat.6 Ethernet cable into the back of the router and the other end into the RJ45 socket on the Control Interface. Remote Maintenance function needs to be enabled by the commissioning technician or qualified installer in possession of the unlock code. Once enabled the User and installer are able to access the remote server via a portal website. A link is emailed to the individual when they are registered along with their User Name and password. This also allows them to use the Alpha App which is free from the App Store or Google Play depending which operating platform being used.

AlphaWeb function
AlphaWeb Function Diagram

The controller should connect to the router automatically if the router supports DHCP functionality, most home routers do. If DHCP has been disabled on the router it can be taken out of the controller and an I.P. address entered manually.

Alpha Innotec Alira LWD Install Guide


Decide on the location of the outdoor unit. There must be adequate air movement around the unit to allow fresh air to enter the rear and for the exhaust air to exit the front. It is vital that the exhaust air cannot be recycled back into the intake, as it passes through the heat pump the temperature falls by as much as 10degC, it doesn’t take long for the unit to freeze once this happens.

Refer to the Operating Manual for the positioning parameters. It is important to note