Maintenance - Heatrae Sadia Megalife 100E Installation Manual

8: Installation - Maintenance
8.1 Maintenance Requirements
The Megalife has been designed and manufactured to require very little maintenance. However, to ensure the
continued optimum performance of the Megalife it should be periodically maintained. This is of particular importance
in hard water areas where limescale can build up on hot surfaces and eventually affect the heating efficiency of either
the immersion heater(s) or primary heating coil. Maintenance should be carried out by a competent person and any
replacement parts used should be authorised Heatrae Sadia Megalife spare parts.
In hard water areas consideration should be given to periodically descaling the immersion heater elements. To do this
the Megalife unit will need to be drained, 8.2 and 8.3 below detail how to drain the unit and remove the immersion
heater(s).
8.2 Draining The Megalife Unit
Switch off the electrical supply to the immersion heater(s), shut down the boiler on indirect units. Turn off the cold
water supply to the Megalife unit by shutting the service valve in the cold water feed pipe from the feed cistern.
Attach a hosepipe to the drain cock having sufficient length to take water to a suitable discharge point below the
level of the unit, at least one metre below the unit is recommended. Open drain cock.
8.3 Descaling Immersion Heater(s)
Open the cover(s) to the immersion heater housing(s) and disconnect wiring from immersion heater(s) thermostat(s).
Remove terminal shroud. Remove thermostat capillary sensors from the pockets on the immersion heater. Unscrew
immersion heater backnut(s) and remove immersion heater from the unit. A key spanner is supplied with the cylinder
unit for easy removal/tightening of the immersion heater(s). Over time the immersion heater gasket may become
stuck to the mating surface. To break the seal insert a round bladed screwdriver into one of the pockets on the
immersion heater and gently lever up and down.
Carefully remove any scale from the surface of the element(s). DO NOT use a sharp implement as damage to the
element surface could be caused. Ensure sealing surfaces are clean and seals are undamaged, if in doubt fit a new
gasket (part number 95 611 822).
Replace immersion heater(s) ensuring the lower (right angled) element hangs vertically downwards towards the base
of the unit. It may be helpful to support the immersion heater using a round bladed screwdriver inserted into one of
the thermostat pockets whilst the backnut is tightened. Replace the terminal shroud. Replace thermostat capillaries
into pocket taking care to put the curly tail capillary in first.
Rewire the immersion heater(s) in accordance with Fig. 04, page 9. Check, close and secure terminal cover.
8.4 Refilling System
DO NOT switch on the immersion heater(s) or primary boiler circuit until the system has been completely
refilled.
Close the drain tap. With the highest hot tap in the system open, turn on the service valve in the cold water feed pipe.
When water emits from the hot tap allow to flow for a short while to purge air and to flush through any disturbed
particles. Close hot tap and then open successive hot taps in system to purge any air. The electrical supply can now
be switched on.
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