3.2.2
A compartment used to enclose the circulator must be designed and constructed specifically for this purpose.
An existing cupboard or compartment may be used providing that it is modified for this purpose. Details of
essential features of cupboard installations are given in BS6798 and BS5546.
3.3
CUPBOARD AND COMPARTMENT VENTILATION:
3.3.1
Where JANUS 6/30 are to be installed in a cupboard or compartment, permanent air vents are required
in the
enclosure at both high and low level for combustion, flue dilution, and cooling purposes. These air vents must
communicate either with a room or internal space, or be direct to outside air.
3.3.2
Minimum effective areas of the permanent air vents required in the enclosure are specified below (ref. BS5440
Pt. 2, Table 2)
Note:
Both air vents must communicate with the same room or internal space, or be on the same wall
to outside air.
Position of
Air from room
Air direct
Air vents
or internal space
from outside
High Level
40cm
2
(6
1
/
2
in)
20cm
2
(3
1
/
4
in
2
)
Low Level
80cm
2
(13in
2
)
40cm
2
(6
1
/
2
in
2
)
Table 2
Permanent Air Vents, Minimum Effective Areas
3.3.3
There are no specific ventilation requirements if the appliance is installed in a room or space, but it should be
noted that if there is a fan in the room or internal space (i.e. extractor fan or cooker hood fan), spillage of
combustion products may occur if the room or internal space is not adequately ventilated to outside air. Where
such installations occur, a spillage test as described in sub-para 3.5.8 must be carried out, and rectification
undertaken where necessary.
3.4
GAS SUPPLY:
Installation of pipework is to be in accordance with BS6891. Pipework from the gas meter is to be of adequate size, and
pipes of a smaller diameter than the appliance are not to be used. The complete installation must be tested for gas
soundness, and purged as detailed in BS6891.
3.5
FLUE SYSTEM:
Detailed recommendations for Flues are given in BS5440 Pt 1. The following points however, are of particular
importance:
3.5.1
The cross-sectional area of the flue serving the appliance must not be less then the area of the flue outlet of the
appliance.
3.5.2
A terminal of a type which has been tested and found satisfactory by British Gas should be fitted at the outlet.
3.5.3
The point of termination must not be within 600mm (2ft) of a opening window, air vent, or any other opening
and should be above roof edge level.
3.5.4
The flue should have a length not exceeding that given in BS5440 Pt 1, Fig. 13 to avoid condensation.
3.5.5
The flue pipe must not be closer than 25mm (1in) to combustible material. For twin wall flue pipe, the 25mm
(1in) distance should be measured from the inner pipe face.
3.5.6
The flue pipe must be secured by support brackets, fitted throughout its length, at intervals of not more than
1.8m (6ft).
3.5.7
If flueing into an existing chimney, the chimney must be swept before connecting the appliance.
3.5.8
The flue system must be tested prior to installation of the appliance by application of a lighted smoke match to
the opening and observing whether all the smoke is pulled up the flue. In certain conditions, there may be
spillage of smoke due to inversion caused by the flue being colder than the outside air. If such occurrences
arise, heat is to introduced into the flue (i.e. by blowlamp) and the spillage test repeated. If either downdraught
or no definite upflow is indicated, this must be investigated and corrected.
3.6
WATER CIRCULATION SYSTEM:
Detailed recommendations for the water circulation system are given in BS6798 and BS5446.
3.6.1
To ensure good circulation in gravity circuits, flow pipes should be designed to run vertically from the water
heater before running laterally. Any lateral run should be less than 2 x the previous vertical run. Pipework
should be installed with a rise towards the vent point.
Note:
For easy removal of the water heater, compression
fittings are recommended.
3
1 0
8.
DEFECT DIAGNOSIS
IMPORTANT: If an electrical defect occurs after installation of the appliance; preliminary earth continuity,
polarity, and resistance to earth checks should be carried out with a multimeter. On completion of any
maintenance/fault-finding task that has required the breaking and remaking of electrical connections, then
checks of continuity, polarity, and resistance to earth must be repeated.
NOTE: When purging or checking gas supplies ensure that, there is adequate ventilation to the room or
cupboard, and all naked lights are extinguished.
SYMPTOM
POSSIBLE CAUSE
RECTIFICATION
a. Pilot fails to light.
i
No gas supply to water heater.
Check for gas at inlet pressure test point on
Multifunctional control.
ii Gas supply not purged.
Purge gas supply pipe in accordance with BS6891.
iii Pilot injector orifice restricted.
Clean or replace pilot assembly.
iv Piezo faulty.
Check/replace piezo unit, lead or pilot burner assembly.
b. Pilot fails to remain lit. i
Thermocoulpe defective.
Replace pilot burner assembly.
ii
Pilot flame out of adjustment.
Adjust pilot flame adjusting screw to provide pilot flame
of approximately 15mm long and just enveloping
thermocouple tip.
c. Main burner fails to
i.
OFF button accidentally depressed.
Press ‘OFF’ button, wait for loud click (approx 3
light
minutes) and repeat lighting procedure.
ii Thermostat overheat.
Draw off hot water from system to allow thermostat to
cool, and ensure burner lights.
iii Thermostat defective.
Replace Multifunctional control.
d. Insufficient hot water.
i. Burner operation cycle too short
Check plumbing, in particular lateral runs.
due to incorrect plumbing.
f. Water temperature
i. Thermostat out of calibration.
Set thermostat for required water temperature or replace
outside usable range.
Multifunctional control.
ii. Gas rate incorrect.
Check burner pressure, main injector for blockage,
replace main injector if faulty.
iii Thermostat phial or capillary
Replace Multifunctional control.
damaged.
IMPORTANT: If a faulty heater control may have resulted in excessively high water temperatures, (above 85ºC,
185ºF), the hot water cylinder should be checked to establish whether it is a SELF-PRIMING type. If so, the circuit
should be drained and refilled to ensure that the air seal between the primary and secondary circuits in the cylinder is
properly established.
