AquaFlo Installation, Maintenance and User Instructions
Page 17 of 24
V 2.01 - October / 2012
The electrical supply to each immersion heater must be fused at 13A via a double pole isolating
switch to BS 3456. The cable must be 2.5mm
2
heat resistant (85°C HOFR) sheathed flex
complying to BS 6141:1981. Do not operate the immersion heater/s until the unit is full of water.
If any sterilisation liquid is in the cylinder do not operate the immersion heater/s as this will
cause premature failure.
The electrical supply must be from a fused supply compliant with local regulations and fitted
by a suitably qualified Electrician.
Energy cutout and cylinder thermostat
(Indirect Only)
As a requirement of Building regulations the AquaFlo units are fitted with a thermal cut-out in
addition to the normal control thermostat. This unit should be fitted to the dedicated boss on
the cylinder and wired to the two port valve controlling the primary flow (see wiring diagram).
Aquaflo unvented indirect Twin coil solar
Indirect twin coil units can be installed in two separate formats:
1. In a solar powered system with a fossil fuel boiler.
2. In a system with two independent fossil fuel boilers.
With either format it is essential the overall installation meets all current legislation including,
in particular, the high limit isolation requirements of Building Regulation G3. This document is
designed to assist in achieving this aim.
Upper coil
The upper coil is connected to the fossil fuel boiler as per the instructions for the AquaFlo single
coil model with the Dual Control thermostat inserted into the middle stat pocket. The wiring
requirements are as depicted in this guide.
Lower coil:
Solar Installation
In a solar powered system the lower coil is connected to the solar heat source. Either primary
coil connection may be utilised as the flow or return. The solar cylinder sensor, supplied as part
of the solar controls, inserts into the lower stat pocket with the supplied grommet. It is necessary
to mount the solar pump in the return pipework with the two port valve (supplied with the
cylinder) installed between the cylinder and the pump.
This valve is of the powered open, sprung closed design and is wired through the high limit stat
which inserts into the upper stat pocket. Two wiring options for high limit isolation are provided
in this guide. The control thermostat is not required in a solar installation.
The remaining upper stat pocket is for the use of a sensor often supplied with a solar control
package which may then provide via display on the solar control panel indication of the water
temperature in the cylinder. NB: not all solar control packs provide this facility.
Lower coil:
Two Boiler Installation
Where the lower coil is to be used with a fossil fuel boiler, the pipework requirements are as
per that of a Stainless Indirect single coil cylinder described earlier in this book. However the
electrical requirements mean the control thermostat inserts into the lower tank stat pocket to
control the boiler input and the limit stat into the upper tank stat pocket. The two port valve may
be installed into either the flow or return pipework. Wiring of the controls are as per the wiring
diagram in this guide.
