Servicing And Maintenance - Dimplex SUTP Mid Range Installation Manual

9. Servicing and maintenance.

9.1. Servicing and maintenance must only be carried out by a competent unvented hot water installer
or by Glen Dimplex UK Limited authorised personnel.
9.2. Before any work whatsoever is carried out on the installation, it MUST first be isolated from the
mains electricity supply.
9.3 Only use spare parts authorised by Glen Dimplex UK Limited. The use of other parts will
invalidate the warranty.
9.4. 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 1). Connect a hosepipe to the drain cock
(see Fig 1) 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.
9.5. 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.
9.6. Remove the cartridge from the pressure reducing valve. Check the strainer and if necessary
remove any debris from in front of it. Replace the cartridge.
9.7 .Check the charge pressure in the expansion vessel and top up as necessary. The charge pressure
should be 3.0 bar.
9.8. 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.
9.9. 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.
9.10. Finally, when the heater is full of water 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.
9.11 In the event of the manual reset cut-out operating, isolate the heater from the mains supply,
investigate and identify the cause of the operation of this cut-out, rectify the fault before manually
resetting the cut-out via the reset button on the cut-out. Finally switch the mains electricity supply back
on.
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