| | | • The THEMA F boiler is compatible with any type of installation. • Pipe sectional areas shall be determined in accordance with normal practices, using the output/pressure curve (diagram 3). The distribution system shall be calculated in accordance with the output requirements of the actual system, not the maximum output of the boiler. However, provision shall be made to ensure sufficient flow so that the temperature difference between the flow and return pipes be less than or equal to 20°C. The minimum flow is 500 l/h. • The piping system shall be routed so as to avoid any air pockets and facilitate permanent venting of the installation. Bleed fittings shall be provided at every high point of the system and on all radiators. • The total volume of water permitted for the heating system depends, amongst other things, on the static head in the cold condition. The expansion vessel on the boiler is pressurised at 1 bar (corresponding to a static head of 5 m w.g.) and allows a maximum system volume of 140 litres for an average temperature of 75°C and a maximum service pressure of 3 bar. This pressure setting can be modified at commissioning stage if the static head differs. | | An additional expansion vessel can be fitted to the system if required, see diagram 6. • Provision shall be made for a drain valve at the lowest point of the system. • Where thermostatic radiator valves are fitted, not all radiators must be fitted with this type of valve, and in particular, where the room thermostat is installed. • In the case of an existing installation, it is ESSENTIAL that the system is thoroughly flushed prior to installing the new boiler using a proprietary product such as Fernox or Sentinel. Contact the product manufacturers for specific details. Filling the system Provision must be made for filling the system at low level. The use of a WRC approved filling loop is strongly recommended, connected as shown in diagram 6. | | |
| | | • Heating system connections - Pipe diam 22 mm • Hot water system connections - Pipe diam 15 mm • Gas connection - Pipe diam 22 mm • Safety valve discharge - Pipe diam 15 mm Water connection Connect the water pipes to the fixing jig using the copper tails supplied, see diagram 5. Warning: To prevent damage to the isolating cocks, do not solder joints or fittings with the copper tails connected. Connect the system pipework to the boiler observing the correct flow and return format as shown in diagram 6. | | Safety valve discharge WARNING. It must not discharge above an entrance or window or any type of public access area. Connect the safety valve discharge pipe to the boiler, the discharge must be extended using not less than 15 m o.d. pipe, to discharge in a visible position outside the building, facing downward preferably over a drain. The pipe must have a continuous fall and be routed to a position so that any discharge of water, possibly boiling or steam, cannot create any danger to persons, damage to property or external electrical components and wiring. Tighten all pipe connection joints. Gas connection • The supply from the governed gas meter must be of adequate size to provide a constant inlet working pressure of 20 mbar (8 in w.g.). To avoid low gas pressure problems, it is recommended that the gas supply is connected using 22 mm pipe. • On completion, the gas installation must be tested using the pressure drop method and purged in accordance with the current issue of BS6891. Gas Safety (Installation and Use) Regulations In your interests and that of gas safety, it is the law that ALL gas appliances are installed and serviced by a competent person in accordance with the above regulations. | | |