Specifications

8.4 DRAINING THE PREMIER PLUS UNIT

Switch off the electrical supply to the immersion heater(s) and/or shut down the boiler.

Turn off the mains water supply to the Premier Plus unit. 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, at

least one metre below the unit is recommended. Open hot water tap nearest to the Premier Plus

to relieve the system pressure. Open drain cock. If water fails to drain from the Premier Plus

vent the unit by manually opening the Temperature/Pressure Relief Valve.

8.5 DESCALING IMMERSION HEATER(S)

Open the cover(s) to the immersion heater housing(s) and disconnect wiring from immersion

heater(s). Remove the thermostat by carefully pulling outwards from the immersion heater. Un-

screw immersion heater backnut(s) and remove immersion heater from the unit. A key spanner

is supplied with the Premier Plus SystemFit 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 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

the thermostat(s) by carefully plugging the two male spade terminations on the underside of the

thermostat head into the corresponding terminations on the element.

Rewire the immersion heater(s) in accordance with Diagram 6. Close and secure terminal

cover(s).

8.6 CHECK 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 3.5 bar. If it is lower than the required set-

ting 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.

8.7 REFILLING SYSTEM

DO NOT switch on the immersion heater(s) or boiler until the system has been completely

relled.

Close the drain tap. With hot tap open, turn on mains water supply. When water ows from the

hot tap allow to ow for a short while to purge air and to ush through any disturbed particles.

Close hot tap and then open successive hot taps in system to purge any air. The electrical sup-

ply can now be switched on.

8.8 BENCHMARK

LOG BOOK

On completion of any maintenance or service of the Premier Plus the Benchmark

“Installation,

Commissioning and Service Record Log Book” should be lled in to record the actions taken

and the date the work was undertaken.