Technical data

16
i. Unscrew the 4 x 5mm hex-socket screws, 2 on either side of the front panel. Remove the front
panel.
ii. Remove all three lower closure panels necessary to gain access to the pipe connections, by un
screwing the 4 x hex-socket screws on each panel.
iii. Position the appliance on a firm, level and substantial concrete base that will absorb vibration and
ensure the unit is well away from any occupied rooms.
iv. Using the adjustable feet, level the unit and tighten the M10 locking nuts on the feet when level.
v. Ensure the heating distribution system has been thoroughly purged of any debris.
vi. Using only plastic flexible pipe such as “Speedfit”, connect the cold feed, ground feed & return
pipes from the Slinky manifold (which can be connected either way round), feed & return pipes
from the underfloor heating manifold (which must be connected the correct way round), according
to the Illustration below. The reason for using flexible pipe is that the heat pump is suspended on
anti-vibration mounts, so the connections must also be flexible.
Using the stickers provided ensure
the flow and return connections are indicated on the manifold.
Flow to
heating system
from heat
pump
28 mm OD
Return from
heating system
to heat pump
28 mm OD
Supply to
ground
28 mm
OD
Return from
ground 28 mm
OD
15 mm
OD cold
feed
Fig 11 Single Compres-
sor heat pump
connections (from the
front of the unit.)
vii. Thread the power supply and timeclock/room thermostat wires from under the Compact into the
control box and connect them to the terminals required, ( see electrical installation section ).
viii. If required fit the optional weather compensation sensor to a North facing wall, and connect with
two-core minimum 0.5mm sq cable (see Section 4.6.4). The use of weather compensation on heat
pumps is unlikely to give any significant cost savings and can actually increase the cost of running a
heat pump. For this reason, Vent-Axia Heat Pumps are supplied with this function disabled in the
software.
ix. For applications where Domestic Hot Water has been specified a 3 port diverting valve (‘W’ plan) is
provided by Vent-Axia and when the timeclock calls for DHW production is used to divert the flow
from space heating to an indirect coil in the DHW tank, (See DHW schematic, Section 4.4). The
diverting valve should be first connection in the heat pumps flow line, before any underfloor
heating manifolds. The valve’s electrical connections are connected to the heat pump’s internal
wiring. (See 4.6.3)
X. Check and rectify any leaks that may be in the plumbing system.
Xi. The appliance should be left for 12 hours after installation before it is turned on, to allow the
refrigerant to settle. The area where the heat pump is installed must be dry and rodent free.