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10.Servicing and maintenance.
10.1. Servicing and maintenance must only be carried out by a competent unvented hot water
installer or by Quantum Heating Limited authorised personnel.
10.2. Before any work whatsoever is carried out on the installation, it MUST first be isolated
from the mains electricity supply.
10.3.
WARNING
: both the primary and secondary systems will contain very hot water that will
scald, therefore care should be taken when opening any joints, seals or valves.
10.4. Only use spare parts authorised by Quantum Heating Limited. The use of unscheduled
spare parts will invalidate the warranty.
10.5. Drain the cylinder – When draining the cylinder, always switch off the boiler and the
immersion heater first. Turn off the water supply at the stopcock (see Fig 5). Connect a hose pipe
to the drain cock (see Fig 5) and route it to a convenient gulley. Open the drain cock and all hot
taps that are served by the cylinder. The cylinder may take several minutes to empty completely.
10.6. In hard water areas it may be necessary from time to time to remove and de-scale the
immersion heater element. Replace the gasket each time it is removed.
10.7. Remove the cartridge from the pressure reducing valve (PRV). Check the strainer and if
necessary remove any debris from in front of it. Replace the cartridge.
10.8 .Check the charge pressure in the expansion vessel and top up as necessary. The charge
pressure should be
3.0 bar
.
10.9. Whilst the hose pipe is connected, the drain cock open and with the immersion heater
removed, the cylinder may be flushed out to remove any debris, sand or lime scale particles that
may have collected in the bottom by using a further hose pipe connected to the cold water main.
10.10. Close the drain cock, disconnect the hose, refit the immersion heater and close all hot
water taps before reopening the stopcock. Allow the cylinder time to fill whilst checking for any
leaks. Release any air from the system by opening each hot water tap individually, starting with
the one furthest from the cylinder.
10.11. Manually lift the expansion relief and temperature and pressure relief valve one at a time,
every 12 months (more frequently in hard water areas) to prevent debris from building up behind
the valve seat. Whilst carrying out this operation, check that the discharge to waste is
unobstructed. Check that each valve seals correctly when released. As the valves are pre-
calibrated, they require no further maintenance.
10.12. Finally switch on the mains electricity supply to the immersion heater and the boiler. As
the system heats up, check again for any leaks and rectify as necessary.
