Technical data

12
Carefully remove any scale from the surface of the
element(s). DO NOT use a sharp implement as dam-
age to the element surface could be caused. Ensure
sealing surfaces are clean and seals are undamaged,
if in doubt t 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 thermostat (Direct
models) or thermostat capillaries into pocket (Indirect
models), rewire, check, close and secure immersion
heater housing cover(s).
7.5 EXPANSION VESSEL CHARGE PRESSURE
Remove the dust cap on top of the vessel. Check the
charge pressure using a tyre pressure gauge. The pres-
sure (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.
7.6 RE-COMMISSIONING
Check all electrical and plumbing connections are se-
cure. Close the drain cock. With a hot tap open, turn on
the cold water supply and allow unit to rell. DO NOT
switch on the immersion heater(s) or boiler until the
unit is full. When water ows from the hot tap allow
to ow for a short while to purge air and ush through
any disturbed particles. Close hot tap and then open
successive hot taps in system to purge any air.
When completely full and purged check system for
leaks. The heating source (immersion heater(s) or
boiler) can then be switched on.
7.7 BENCHMARK
TM
LOG BOOK
On completion of any maintenance or service of the
Premier Plus the Benchmark
TM
“Installation, Com-
missioning and Service Record Log Book” should be
lled in to record the actions taken and the date the
work was undertaken.
7.3 STRAINER
Turn off the cold water supply, boiler and immer-
sion heaters. The lowest hot water tap should then
be opened to de-pressurise the system. Remove the
Pressure Reducing Valve housing by unscrewing the
four securing screws with the Allen key supplied.
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 tted, DO
NOT use any other type of sealant. Ensure the four
securing screws are tightened equally.
7.4 DESCALING IMMERSION HEATER(S)
Before removing the immersion heater(s) the unit
must be drained. Ensure the water and electrical
supply and boiler are OFF before draining. Attach
a hosepipe to the drain cock having sufcient 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
by carefully pulling outwards from the immersion
heater. Unscrew immersion heater backnut(s) and re-
move immersion heater from the unit. A key spanner is
supplied with the Premier Plus 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
7.0 MAINTENANCE
7.1 MAINTENANCE REQUIREMENTS
Unvented hot water systems have a continuing main-
tenance requirement in order to ensure safe working
and optimum performance. It is essential that the
Relief Valve(s) are periodically inspected and manu-
ally opened to ensure 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.
7.2 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.
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). Re-
move 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
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.