16
5.2.3 Adjusting the feet
The product is equipped with three factory fitted
feet (F), adjustable from 0-40 mm. Unscrew the
feet a minimum of 15 mm from the bottom of the
product. Then adjust the feet individually until the
product is standing firmly and level vertically and
horizontally.
5.3 Intermittent discharge from tundish
1. Turn off the electrical supply to the immer-
sion heater.
2. Turn off cold water supply valve.
3. Open a hot tap.
4. Turn the knob (K) on the Temperature and
Pressure Relief Valve clockwise and hold in
this position for 30 seconds (see below).
5. Check pre-charge on vessel and adjust
pressure if necessary.
6. Open cold water supply valve.
7. When water flows through open tap, close
tap. Turn on electrical supply to the immer-
sion heaters.
5.4 Continous very hot water discharge from
tundish
This indicates a malfunction of a thermal cut-out,
operating thermostat or the combined tempera-
ture and pressure relief valve. Turn off the electri-
cal supply to the immersion heater and also iso-
late any indirect unit connected to the vessel or
coil. Contact the installer or competent engineer.
5.5 Expansion vessel maintenance
The expansion vessels require annual mainte-
nance by a competent person and the precharge
pressure must be restored to the original value.
An annual visual inspection is recommended.
Important: to check the precharge the expansion
vessel must be completely empty of water. if the
pressure is different from the value shown on the
F
F
K
F
label it must be restored to the original value.
Do not remove expansion vessel without depres-
surising the cylinder and draining 10 litres of water
from the drain valve at the base of the cylinder
5.6 Warranty
Cylinder should be serviced annually (as below)
and logbook should be updated in order to vali-
date warranty. Logbook and service records act
as warranty document. For terms of warranty see
Service logbook at rear of manual.
5.7 Service procedure
The following maintenance work has to be carried
out annually by a competent person:
1. Inspection of pressure/temperature relief
valve and expansion relief valve.
2. Manually operate each valve by twisting the
operating cap, and check if water flows un-
obstructed via the tundish to the discharge
point.
3. Ensure that both valves re-seat satisfactorily.
4. Turn off mains water supply and open near-
est hot water tap to depressurise the DHW
system.
5. Check the expansion vessel.
6. If the pressure is below 3 bar, top up with
a suitable air pressure pump to pressure
shown on vessel label.
7. Complete the service section of Benchmark/
Cylinder Commissioning Checklist included
in the inside back pages of these instructions.
8. Remove , clean and replace line strainer.
9. The immersion heater element must be
removed for inspection on service after 5
years. The threads must be checked for cor-
rosion. If signs of corrosion are evident, the
element must be replaced. Subsequently
the element must be removed and exam-
ined every 3 years. Failure to do so in ar-
eas of aggressive water may result in the
element separating from the cylinder with
consequential escape of water.
10. Visual inspection of all valves, external fit-
tings, immersion heaters and electrical con-
nections.
5.8 Discharge
Discharge pipes must be metal or suitably tem-
perature rated as defined by G3 building Regula-
tions. The pipe should have a continuous fall and
should terminate in a safe and visible place.
Downward discharges at low level, i.e. up to 100
mm above external surfaces such as car parks,
hard standings, grassed areas etc. are accept-
able providing that where children may play or
