RAYBURN
COOKERS
INSTALLATION
THIS SECTION
OTHER SECTIONS
CENTRAL HEATING
Heatranger Model 368K
Direct, Sealed or un-vented systems must not be used with this model
With this model it is normal installation practice to pump-assist the central heating circuit, whilst retaining gravity circulation for the domestic hot water pipe-work.
The heating pipe-work should be a two-pipe, small bore system with the radiators having the appropriate control valves and lock-shield valves for balancing. The control valves may be thermostatic, but it is recommended that at least one radiator should remain in operation with a manual valve, to serve as a heat-leak
An injector tee (supplied with the Rayburn) must be fitted as shown below, to ensure that the gravity hot water circulation continues even when the pump is in operation. Note the correct position for this fitting. Drain-cocks should be fitted at the lowest points of the system.
The system must be fully flushed through and filled with an appropriate corrosion inhibitor
Since radiator sizes and outputs vary considerably, it is not possible to quote the actual number of radiators that can be served by each model. It is more appropriate to refer to the radiator manufacturer's rated output (kW/hr) and to match this to the Rayburn's boiler output specification, which is a maximum of 18 kW/hr ( this figure does not include the heat required for the domestic hot water production)
Control over the central heating is normally achieved by switching the circulating pump and boiler burner, using a time-clock and/or room thermostat. It is essential that the pump always operates whenever the boiler burner is being called for.
To prevent the possibility of the radiators becoming warm from gravity circulation when the pump is off, it is good practice to fit a check valve or motorised zone valve as shown in the diagram. In the latter case this should be wired in parallel to the pump.
The system must be installed in accordance with local water bylaws, Building Regulations and British standards and we strongly encourage that the plumbing and electrics be carried out by a competent person.