13.1
Tell the user how to operate the appliance and hand over
the Users Instructions leaflet.
13.2
Tell the user what to do if the heating system is not to be
used in frosty weather.
13.3
Tell the user the sealed system set pressure.
13.4
Tell the user of the importance of regular servicing.
Worcester Heat Systems Ltd. offer a comprehensive maintenance
contract.
13.5
Set the system controls to the user’s requirements.
13.6
If an external programmer has been fitted which has a
programmable domestic hot water facility then it is suggested
that this be set to Continuous or the equivalent.
14.1 SERVICING
To ensure continued efficient operation of the appliance it must
be checked and serviced as necessary at regular intervals. The
frequency of servicing will depend upon the particular
installation conditions and usage, but once per year should
generally be adequate. The extent of the service required by the
appliance is determined by the operating condition of the
appliance when tested by fully qualified engineers.
Any service work must be carried out by competent engineers
such as British Gas or Corgi registered personnel.
14.2 PRE-SERVICE INSPECTION
Check that the flue terminal and the terminal guard, (if fitted), are
clear.
If the appliance is in a compartment, check that the ventilation
openings in the compartment door or walls are clear. See Section
6 - Air Supply.
Check the system and remake any joints or fittings which show
signs of leakage.
Refill, vent and re-pressurise as described in Section 12.2.
Operate the appliance and the system taking note of any faults.
Measurement of the Flue Gases
For consistency of results of the flue gas measurements it is
necessary to have a constant output and for the appliance to be
at equilibrium.
Turn on a tap to create a hot water demand.
Wait until the appliance reaches thermal equilibrium (approx. 10
minutes).
Remove the test point sealing screw on the appliance top panel.
See Fig. 30.
Connect to the test point with a piece of tubing.
Expected measurements should be between:
For Natural Gas:
For Propane:
When calculating the equivalent flue length a flue bend is
equivalent to 750mm of straight flue.
After taking the measurement replace and tighten the sealing
screw.
IMPORTANT
Disconnect the electrical supply at the mains and turn off the
gas supply at the gas service cock on the appliance before
servicing.
After completing the service always test for gas soundness as
indicated in BS 6891.
14. Inspection And Service
13. Instructions To The User
18
Equivalent flue
Carbon
Carbon
length (metres)
Dioxide (%)
Monoxide (%)
0.5
6.9
0.0008
1.0
7.0
0.0009
1.5
7.1
0.0010
2.0
7.3
0.0012
2.5
7.4
0.0013
Equivalent flue
Carbon
Carbon
length (metres)
Dioxide (%)
Monoxide (%)
0.5
7.9
0.0017
1.0
8.0
0.0020
1.5
8.2
0.0024
2.0
8.5
0.0030
2.5
8.8
0.0035
Fig. 28. User controls.
Reset button
Mains indicator
C.H. temperature control
and on/off knob
System
pressure
gauge
