Maintenance - Heatrae Sadia PremierPlus PES170D Installation And User Manual

8.0 MAINTENANCE

8.1 MAINTENANCE REQUIREMENTS
Unvented hot water systems have a continuing maintenance requirement in order to ensure safe working and
optimum performance. It is essential that the relief valve(s) are periodically inspected and manually opened to en-
sure no blockage has occurred in the valves or discharge pipework. Similarly cleaning of the strainer element and
replacement of the air in the expansion vessel will help to prevent possible operational faults.
The maintenance checks described below should be performed by a competent installer on a regular basis, e.g.
annually to coincide with boiler maintenance.
8.2 SAFETY VALVE OPERATION
Manually operate the temperature/pressure relief valve for a few seconds. Check water is discharged and that it
flows freely through the tundish and discharge pipework. Check valve reseats correctly when released. NOTE: Water
discharged may be very hot!
Repeat the above procedure for the expansion valve.
8.3 STRAINER
Turn off the cold water supply, boiler and immersion heaters. The lowest hot water tap should then be opened to
de-pressurise the system. Remove the pressure reducing valve by unscrewing it housing. Pull the reducing valve
cartridge from the check valve housing to access the strainer mesh. Wash any particulate matter from the strainer
under clean water. Re-assemble ensuring the seal is correctly fitted, DO NOT use any other type of sealant.
8.4 DESCALING IMMERSION HEATER(S)
Before removing the immersion heater(s) the unit must be drained. Ensure the water, electrical supply, boiler and
solar primary circuit are OFF before draining. Attach a hosepipe to the drain cock having sufficient length to take
water to a suitable discharge point below the level of the unit. Open a hot tap close to the unit and open drain
cock to drain unit.
Direct models:
Open the cover(s) to the immersion heater housing(s) and disconnect wiring from the thermostat mounted on top
of the immersion heater(s). Remove the thermostat capillary sensors by carefully pulling outwards from the immer-
sion heater. Unscrew immersion heater backnut(s) and remove immersion heater from the unit. A key spanner is
supplied with the PremierPlus solar unit for easy removal/tightening of the immersion heater(s). Over time the im-
mersion 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.
Indirect models:
Open the cover(s) to the immersion heater housing(s) and disconnect wiring from immersion heater(s). 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 Premier Plus Solar 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.
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 thermostats capillaries into pockets, rewire,
check, close and secure immersion heater housing cover(s).
8.5 PREMIER PLUS SOLAR EXPANSION VESSEL CHARGE PRESSURE
Remove the dust cap on top of the vessel. Check the charge pressure using a tyre pressure gauge. The pressure
(with system de-pressurised) should be 3.5bar. If it is lower than the required setting it should be re-charged using
a tyre pump (Schrader valve type). DO NOT OVER CHARGE. Re-check the pressure and when correct replace the
dust cap.
8.6 RE-COMMISSIONING
Check all electrical and plumbing connections are secure. Close the drain cock. With a hot tap open, turn on the cold
water supply and allow unit to refill. DO NOT switch on the immersion heater(s) or boiler until the unit is full.
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