Maintenance - Heatrae Sadia MULTIPOINT 75 Fitting Instructions And User Manual

MINIMUM SIZE OF MINIMUM SIZE OF
VALVE OUTLET
DISCHARGE PIPE D1 DISCHARGE PIPE D2
SIZE
FROM TUNDISH
G 1/2 15MM 22mm
28mm
35mm
G 3/4 22MM 28mm
35mm
42mm
G 1 28MM 35mm
42mm
54mm
Table 1. Sizing of copper discharge pipe (D2) for common T&P relief valve
Safety device
(e.g. Temperature
relief valve)
Metal discharge pipe (D1) from
Temperature relief valve to tundish
500mm maximum
300mm
minimum
Discharge pipe (D2) from tundish,
with continuous fall. See Building
Regulation G3 section 3.9d i-iv,
Table 4 and worked example
Figure 5. Schematic discharge pipe arrangement.
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RESISTANCE CREATED BY
MAXIMUM RESISTANCE
EACH ELBOW OR BEND
ALLOWED, EXPRESSED
AS A LENTGH OF
STRAIGHT PIPE (I.E. NO
ELBOWS OR BENDS
UP TO 9M 0.8M
UP TO 18M 1.0M
UP TO 27M 1.4M
UP TO 9M 1.0M
UP TO 18M 1.4M
UP TO 27M 1.7M
UP TO 9M 1.4M
UP TO 18M 1.7M
UP TO 27M 2.3M
sizes.
Tundish
Discharge below
(Building Regulation
G3 section 3.9d gives
alternative points
of discharge)
Fixed grating
Trapped
gully
7.0 COMMISSIONING
7.1 Do not switch on the electrical supply until the Multipoint has been filled
with water and checked for leaks.
7.2 Check that all installation, electrical and discharge pipe requirements
have been met.
7.3 Check that all water and electrical connections are tight.
7.4 Open a hot water tap, turn on mains water supply to the Multipoint.
7.5 Allow Multipoint to fill and leave hot tap running for a short while to
purge any air and flush out the pipework. Close the hot tap and check
the system for leaks.
7.6 Manually test the operation of the Temperature/Pressure Relief Valves
and the Pressure (expansion) Relief Valve. Ensure water flows freely
from the valves and through the discharge pipes.
7.7 Switch on the electrical supply. The indicator lights will illuminate during
heating. When the set temperature is reached the indicator lights will go
out.
7.8 The set temperature can be adjusted by rotating the thermostat
controls located inside the terminal cover. It is recommeded that both
thermostats are set at position 6 (approximatley 60°C) however they
can be adjusted between settings 1 to 7 (5°C to 75°C). In hard water
areas it is advised that the maximum temperature is restricted to
prevent build up of scale.

8.0 MAINTENANCE

Little maintenance is required, however in hard water areas the unit will
require periodic descaling to ensure efficient operation. To descale the unit:
8.1 Switch off and disconnect the electrical supply. Turn off the water
supply to the unit.
8.2 Open a hot tap to relieve any system pressure.
8.3 Remove the terminal cover by removing the five supporting screws
holding it in place.
8.4 Drain water by opening internal drain cocks.
8.5 Unclip the expansion vessel retaining clip and locate the expansion
vessel into the nest detail at the front on the right (see Figure 6
overleaf).
8.6 Disconnect the electrical terminals to the element and the earth link to
the earthing stud. Withdraw the thermostat and thermal cut-out capillary
tubes from the pockets on the element plate.
8.7 Remove the element plate assembly by unscrewing the five securing
screws. Tapped jacking holes are provided (NOTE: a quantity of water
may still be present in the container, it is recommended that a container
be placed under the unit to collect any spillage).
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