Oversink and Undersink Water Heater
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Keep the hot water inside the appliance at a temperature of not below 55°C;
In case a prolonged absence let water run from taps and showers for a few minutes;
Keep showers and taps clean of scale;
The thermostat is factory-set to max. value; to change the setting disconnect the power supply then remove the
protection cover, turn the thermostat knob towards “+” to increase or “-“ to decrease the temperature. Refer to the
relevant notch located on the thermostat. To prevent the formation of “legionella” an adjustment close to the factory
setting (towards the “+” notch) is advisable.
6
COMMISSIONING SYSTEM
IMPORTANT: It is the responsibility of the installer to ensure that the system is properly commissioned.
The thermostat on the immersion heater should be adjusted to trip at 60°C. This is the ideal temperature to prolong
element life in hard water areas. Scale on the sheath builds up more rapidly at temperatures above this causing the
element to overheat and premature failure can occur. Higher temperatures without additional controls would result
in scalding. In known hard water areas the use of a scale inhibitor is also recommended.
In addition to the thermostat the thermal cut-out will switch power off to the element should the thermostat malfunction,
causing an excessive rise in water temperature. The thermal cut-out can be reset manually after the fault has been
corrected
6.1
Electrical Check
Check that all wiring including earth wiring, has been installed correctly, conform to current regulation and
satisfactory electrical test and inspection certificate has been completed.
Check all electrical covers are correctly fitted;
Check tundish is positioned so that any spillage or spray from the tundish would not contact any electrical
components.
Check all wiring connections have been made.
Undertake an earth continuity check and reverse polarity check.
6.2
Pre-Fill Check
Check that no valves are fitted between water heater and the combination valve.
Check the control valve, tundish and discharge pipes are corrected installed to conform to the Building
Regulation G3.
Check all pipes connections are tight and no joints have been left unsoldered.
Check all drain cocks are closed.
6.3
Filling the water heater
Close all isolating valves.
Close all taps.
Open the incoming water mains stopcock.
Turn on mains water, allow system to fill up to first isolating valve. Turn on hot taps. Open isolating valves and
allow the water heater to fill and let water pass through the system to the open hot tap, this will expel most of air
from the system and fill the water heater vessel.
Systematically open all hot and cold taps to purge air.
Check system for leaks.
Check no water is discharging from safety relief valve.
Safety relief valve – check its operation; with the water supply on, turn the safety relief valve test knob and check
water discharges to tundish, ensure the valve closes after testing.
Discharge pipe (D1) – open either T&P or PRV gradually to produce all full bore discharge into tundish and D2 and
check there is no back pressure, and that the water flows freely to drain.
