35
3.1 Commission the Boiler
Automatic Air Vent:
This is built into the pump. Leave
the cap open during and after commissioning.
Manual Air Vent:
This must be used to remove as much
air as possible before firing the burner.
Warning: Do not attempt to start this boiler unless
the primary circuit has been filled with water.
Preliminary Electrical System Checks
These checks must be carried out prior to attempting to
start the boiler. They are, Earth Continuity, Short Circuit,
Polarity & Resistance to Earth.
Flush the System
The system must be flushed in accordance with BS7593
and the flushing agent manufacturer
$
s instructions.
Further guidance can be obtained from BS5449 Section
5.
Gas Soundness
Purge and test for soundness in accordance with BS6891
or I.S. 813. The inlet pressure test point of the gas valve
is indicated opposite. The appliance gas cock operation is
shown in Fig. 9A page 26.
Unvented Domestic Hot Water System
1. Open one or more hot water taps.
2. Turn on mains water supply and observe air free
water issuing from tap(s)
3. Close tap(s) and check mains water pipework for
leaks
4. Check that all factory-made plumbing connections
are tight and leak free (and have not loosened in
transit).
5. Manually operate both the Temperature &
Pressure Relief Valve and the secondary pressure
relief valve and ensure that the discharge from
these valves emerges safely. Close them again
with a “snap” action.
Guideline times for the initial heat-up and recovery
for a nominal 50 °C temperature rise (e.g. 15 °C -
65 °C) within the store are:
Unit Heat-up
Recovery*
90 Litre
18 min.
15 min.
115 Litre
22 min.
18 min.
150 Litre
30 min.
23 min.
* From previous draw-off of 70% of volume.
Sealed Primary System
1. Ensure that gas supply is turned OFF at the gas
cock.
2. Leave the boiler switched OFF at the selector switch
but turn both the CH and DHW control knobs clockwise.
3. Move the indicator lever on the diverter valve head to
the mid position and push in so that it “latches”.
4. Check that the isolating valve on the by-pass link is
OPEN (slot in-line with body).
5. Attach a length of hose to the outlet of the manual
vent (1/4” manometer tube is suitable). Open the vent
using a radiator key.
6. Open the automatic air vent cap (above the pump) by
one turn. Check that filling loop is connected and
supplied with water.
7. Open both valves on the filling loop and fill system
with water. Allow water to flow from the manual vent
until air is no longer discharged.
8. Turn the (LH) selector switch clockwise to the DHW
position and use the HW/ENTER button on the
programmer to select hot water on ALL DAY or 24HR
NOTE:
Full details of how to set up and use the
programmer are in the User
$
s Instructions.
9.The pump and diverter valve should now operate
allowing more air to be expelled. (Free the pump
spindle if it appears to be sticking).
10. The boiler control will go to lockout after about a
minute. Close the manual vent. Reset using the selector
knob, turn the gas ON and allow the boiler to start
heating the cylinder contents.
11. After approx. 5 minutes, central heating can be
selected by using the selector switch and programmer.
12. If a fault is suspected, consult the list of Error Codes
on page 42.
Inlet Pressure
Point
Outlet Pressure
Point
© Baxi Heating UK Ltd 2012
