VOKERA Mynute EHE Installation & Servicing Instructions Manual - page 8
6
3.6.7
LOW PRESSURE SEALED SYSTEM
An alternative method of filling the system would be from
an independent make-up vessel or tank mounted in a
position at least 1 metre above the highest point in the
system and at least 5 metres above the boiler (see fig. 5a).
The cold feed from the make-up vessel or tank must be fitted
with an approved non-return valve and stopcock for isola-
tion purposes. The feed pipe should be connected to the
return pipe as close to the boiler as possible.
3.6.8
FREQUENT FILLING
Frequent filling or venting of the system may be indicative
of a leak. Care should be taken during the installation of the
appliance to ensure all aspects of the system are capable
of withstanding pressures up to at least 3 bar.
Fig. 6a
3.6.5
EXPANSION VESSEL
The appliance has an integral expansion vessel to accom-
modate the increased volume of water when the system is
heated. It can accept up to 8 litres (25kW) or 10 liters
(29&35kW) of expansion from within the system, generally
this is sufficient, however if the system has an unusually
high water content, it may be necessary to provide addi-
tional expansion capacity (see 6.19).
3.6.6
FILLING POINT
An approved method for initial filling of the system and
replacing water lost during servicing etc. is required (see
fig. 5). This method of filling must comply with the current
Water Supply (Water Fittings) Regulations 1999 and Water
Bylaws 2000 (Scotland).
Fig. 5
control valve
temporary
connection
control valve
supply pipe
double check
valve
flow/return
pipe
3.7
ELECTRICAL SUPPLY
The appliance is supplied for operation on 230V @ 50Hz
electrical supply; it must be protected with a 3-amp fuse.
The method of connection to the mains electricity supply
must allow for complete isolation from the supply. The
preferred method is by using a double-pole switch with a
contact separation of at least 3,5mm (3° high-voltage
category). The switch must only supply the appliance and
its corresponding controls, i.e. time clock, room thermostat,
etc. Alternatively an un-switched shuttered socket with a
fused 3-pin plug both complying with BS 1363 is accept-
able.
3.8
MOUNTING ON A COMBUSTIBLE SURFACE
If the appliance is to be fitted on a wall of combustible material,
a sheet of fireproof material must protect the wall.
3.9
TIMBER FRAMED BUILDING
If the appliance is to be fitted in a timber framed building, it
should be fitted in accordance with the Institute of Gas
Engineers publication (IGE/UP/7) ‘Guide for Gas Installa-
tions in Timber Frame Buildings’.
3.10
INHIBITORS
Vokera recommend that an inhibitor - suitable for use with
copper and aluminium heat exchangers - is used to protect
the boiler and system from the effects of corrosion and/or
electrolytic action. The inhibitor must be administered in
strict accordance with the manufacturers instructions*.
*Water treatment of the complete heating system – includ-
ing the boiler – should be carried out in accordance with BS
7593 and the Domestic Water Treatment Association’s
(DWTA) code of practice.
Fig. 5a
Make-up vessel
or tank
Automatic
air-vent
Non-return
valve
Stopcock
5.0 metres minimum
Heating
return