Grant QR Range, Инструкция по установке, обслуживанию и эксплуатации

Страница: 23 / 44

Page 23 Section 7: Maintenance
! NOTE !
Servicing details should be entered in the commissioning
and service log in Appendix C at the back of these
instructions.
7.1 SERVICING AND MAINTENANCE
1. Servicing and maintenance must only be carried out by
a competent unvented hot water installer, or by Grant
Engineering (UK) Limited authorised personnel.
2. Before any work whatsoever is carried out on the installation,
it MUST first be isolated from the electricity supply.
! 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.
3. Only use spare parts authorised by Grant Engineering (UK)
Limited. The use of unauthorised spare parts will invalidate
the guarantee.
4. Drain the cylinder – When draining the cylinder, always
switch off the boiler/heat pump and the immersion heater
first. Turn off the water supply at the service valve or mains
stopcock.
Connect a hose pipe to the drain cock (see Figure 2-2) and
route it to a convenient gully. Open the drain cock and all hot
taps that are served by the cylinder. The cylinder may take
several minutes to empty completely.
5. 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.
6. Check any in-line strainers which may be fitted in the cold
supply to the cylinder and clean if necessary.
7. Remove the expansion relief valve cartridge. Check and
clean valve seat. Replace cartridge. Refer to Section 7.3 for
further information.
8. Check the charge pressure in the expansion vessels and top
up as necessary. Refer to Section 7.4 for further information.
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. Close the drain cock, disconnect the hose, refit the
immersion heater and close all hot water taps before re-
opening 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.
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.
12. Finally switch on the mains electricity supply to the immersion
heater and the boiler/heat pump. As the system heats up,
check again for any leaks and rectify as necessary.
7.2 INLET MANIFOLD ASSEMBLY
The inlet manifold assembly should not, under normal
circumstance, require any maintenance. During annual servicing
it may be necessary to inspect and/or clean the expansion relief
valve cartridge. The frequency of cleaning will depend on the local
water conditions.
7.3 EXPANSION RELIEF VALVE CARTRIDGE
1. Isolate the cold water supply.
2. Remove the un-sprung circlip retaining the expansion relief
valve cartridge in the inlet manifold body. See Figure 4-1.
3. Carefully remove the expansion relief valve cartridge from
the inlet manifold body. It is a push fit type fitting, so gently
pull on the body of the cartridge until it is released.
4. Clean valve seat face and seating - do not scratch or
damage either seat face or seating.
5. Refit in reverse order.
Ensure that the circlip is fully inserted into its seat.
Expansion valve cartridge (Grant UK product code: GCS08).
! CAUTION !
Upon re-fitting the circlip used to retain the push-fit
expansion relief valve into the inlet manifold body, ensure
the circlip is fully inserted into its seat.
7 MAINTENANCE