2.5 ELECTRICAL SUPPLY
Mains supply: 230V ~, 50 Hz, 180 watts.
External fuse: 3A., Internal fuses: 2AT HRC(F1), and 1 AF (F2). 2.6 GAS SUPPLY
The boiler requires 2.76 m3/h (97.5 ft3/hr) of natural gas with a calorific value of 37.78 MJ/m3 (1014 Btu/ft3) or 1.07 m3/h (37.8 ft3/hr) of propane with a calorific value of 95.65 MJ/m3 (2568 Btu/ft3). The meter governor should deliver a dynamic pressure of 20 mbar (8in w.g.) at the appliance, equivalent to a pressure of about 19-19.5 mbar at the gas valve on natural gas or 37.0 mbar (14.8in w.g.) at the appliance for propane.
The gas meter and supply pipes must be capable of supplying this quantity of gas in addition to the demand from any other appliances being served. The table below gives an indication of limiting gas pipe lengths and the allowance to be made for fittings. Refer to BS6891 for further information.
The complete installation, including the gas meter, must be tested for soundness and purged. Refer to BS 6891.
| Total length of gas supply pipe | Pipe size |
| | (metres) | | (¯mm) |
| 3 | 6 | | 9 | | 12 | |
Gas | | | | Propane | | |
Discharge | 1.5 | Ð | | Ð | | Ð | 15 |
Rate | 8.0 | 5.2 | | 4.2 | | 3.6 | 22 |
| 15.9 | 8.8 | | 8.5 | | 7.2 | 28 |
(m3/hr) | | | Natural Gas | | |
| 8.7 | 5.8 | | 4.6 | | Ð | 22 |
| 18.0 | 12.0 | | 9.4 | | Ð | 28 |
| | | | | | | |
Note: Each fitting used in the gas line from the meter is equivalent to a length of straight pipe which must be added to the straight pipe length to give the total length.
i.e.: Bend = 0.5 metres, Tee = 0.5 metres, 90¡ Bend = 0.3 metres.
2.7 PACKING
The appliance and flue components are packaged separately.
2.8 GENERAL INSTALLATION
The appliance is for connection to a sealed system only.
The specified ventilation openings made into a wall or compartment door must not be obstructed.
If the appliance is to be fitted into a compartment then the compartment must conform to the requirements of BS 6798: 1987: Section 7.
Do not place anything on top of the appliance.
The clearances specified for servicing must be maintained.
2.9 FLUE
The appliance has a multi-directional fanned flue system.
The standard telescopic flue assembly length is from 127mm to 350mm.
Extension flue lengths available are from 350mm to 2500mm. An optional vertical flue kit to provide for flue lengths up to 3000mm including vertical flue terminal.
A terminal guard, Type K2, GC 393 553, is available from Tower Flue Components, Vale Rise, Tonbridge, TN9 1TB.
Do not allow the flue terminal fitted to the outside wall to become obstructed or damaged.
A kit for internal fixing of the flue is available separately.
2.10 CONTROLS
The electronic control system and gas valve modulate the heat input in response to the domestic hot water temperature and central heating setting between minimum and maximum.
The Central Heating Temperature control knob provides for the selection of domestic hot water only (Turned fully anti-clockwise) or central heating and domestic hot water (Turned clockwise).
A facia mounted programmer is available as an optional extra. A remote mounted programmer may be connected to the appliance.
There is provision for the connection of a mains voltage room thermostat and/or a frost thermostat.
The electronic controls prevent rapid cycling of the appliance in the central heating mode.
2.11SYSTEM NOTES IMPORTANT
Check that no dirt is left in either the gas or water pipework as this could cause damage to the appliance. The heating system should be flushed and treated in accordance with the recommendations of BS 7593:1992. Thoroughly flush cold water mains supply and purge the gas supply before finally connecting the appliance.
The water pipe connections throughout a sealed system must be capable of sustaining a pressure of up to 3 bar.
Radiator valves must conform to the requirements of BS 2767:1991.
The relief valve discharge must be directed away from any electrical components or where it would cause a hazard to the user.
A drain cock to BS 2879 must be fitted to the lowest point of the system.
For circuit design purposes it is important that due note is taken of the information given in Table 3, section 3 relating to the available pump head.
2.12SHOWERS, BIDETS, TAPS AND MIXING VALVES
Hot and cold taps and mixing valves used in the system must be suitable for operating at mains pressure.
Thermostatically controlled shower valves will guard against the flow of water at too high a temperature.
Hot and cold mains fed water can be supplied direct to an over- rim flushing bidet subject to local Water Company requirements. With all mains fed systems the flow of water from the individual taps will vary with the number of outlets operated simultaneously and the cold water mains supply pressure to the property. Flow balancing using ÒBall-o-FixÓ type valves is recommended to avoid an excessive reduction in flow to individual outlets.
2.13 SAFETY CONSIDERATIONS
The appliance must not be operated in a waterless condition. The appliance must not be operated with the boiler inner casing cover removed.
Work must not be carried out on the appliance without the gas and electricity supplies being switched off.
Checks must be made to ensure that the ventilation openings made into walls and partitions are unobstructed and the correct size.
2.14 OPERATION
Domestic Hot Water: With a demand for hot water the burner will light at its maximum setting and then automatically adjust its output to maintain the temperature of the delivered water. When hot water is no longer required, the burner will extinguish. The fan and pump may continue to run for a short period to dissipate the residual heat from the appliance.
Central Heating: With a demand for heating the burner will light at its minimum setting and gradually increase to give a controlled temperature rise. When the required heating temperature is achieved the output of the appliance is then automatically adjusted to maintain the temperature of the system. The output can reduce down to a minimum of 7.5 kW. If the system no longer requires even the minimum output to maintain the desired room temperature the burner will extinguish. The fan and pump may continue to run to dissipate the residual heat from the appliance. The appliance will remain off for a fixed period before re-lighting to automatically meet the system requirements.
Domestic Hot Water and Central Heating: The appliance will supply heat to the central heating system as required. A demand for domestic hot water at a tap or shower will override the central heating requirement for the period of the domestic hot water demand. When hot water is no longer required the appliance will return to the central heating state and its normal mode of operation. The fan may continue to run to dissipate the residual heat from the appliance as necessary.
2.15 DOMESTIC SUPPLY
Devices capable of preventing the flow of expansion water must not be fitted unless separate arrangements have been made.
