
7
Installation and operating instructions
WARNING: All water heaters must be fitted with temperature control to ensure that
the domestic water is not heated to temperatures above 60°C
The following safety devices must be fitted to the water heater when used in an un-
vented system:
1 Stop Valve: This allows the system to be isolated from the cold water supply.
2 Combined Pressure Reducing Valve and Cold Fill Manifold: The PRV is designed to stabilise the inlet
water pressure at 3 bar. The unit comprises the PRV and a manifold containing a check valve, a cold
water balancing port and a preset pressure relief valve. The pressure relief valve is set at 6bar.
3 Expansion vessel: Expansion must be accommodated using an Expansion vessel. The Expansion vessel
must be sized to accommodate the maximum expansion of the system and should be suitable for use
with potable water.
4 Drain Valve: This allows the water heater to be drained for service or removal.
5 Tundish: The Tundish must be fitted to the discharge of the safety valves. It provides an air break and
allows the user to see the release of water from the valves.
6 Temperature and Pressure Relief valve (T&P valve): this ensures that the temperature of the stored
water cannot exceed 100
o
C and in this scenario will vent any excess pressure.
7 Blending (Mixing) Valve: The blending valve limits the temperature of the delivered water by mixing it
with cold water as required. The delivered water temperature should not exceed 50°C.
8 Upper Coil Temperature Sensor Dry Pocket: This is used for the insertion of the high limit and thermo-
stat control. It is essential that suitable temperature controls are used to prevent the water from
reaching excessive temperature. A high limit thermostat with a manual reset device is also supplied to
allow interruption of the energy supply when the water temperature reaches 90°C. The correct instal-
lation and wiring of this device is essential for the safe operation of the water heater.
9 Zone Valve: The recommended water storage temperature is 60°C. The water heater thermostat
should be wired to ensure that the energy supply to the water heater is interrupted if the water tem-
perature exceeds 60°C. The zone valve is used for this purpose.
10 Lower Coil Temperature Sensor Dry Pocket: This is used to insert temperature sensor for the control of
the lower coil. In a solar water heating system, the solar water heater sensor will normally be fitted
here. It is essential that suitable temperature controls are used to prevent the water temperature
exceeding 60°C.
11 Pressure Gauge: This is used to monitor pressure in the system from 0-6 bar.
Failure to fit these essential safety devices will invalidate the warranty and may cause a
dangerous installation leading to property damage, injury or loss of life.