COMBI A - Instruction Manual

12.3 Fitting the Coaxial

12.3 Fitting the Coaxial Flue (Ø 60 / 100 Vertical) NOTE: SEE PAGE 24 FOR MAXIMUM AND MINIMUM FLUE RUNS. CONTENTS: 1X SILICONE O-RING (60mm) 1X CONICAL ADAPTOR (60/100mm) 1X VERTICAL FLUE KIT (80/125mm) 3X SCREWS The vertical flue kit is supplied with a specially designed weather proof terminal fitted, it can be used either with a flat roof or a pitched roof. The Vertical flue kits useable lengths with the pitched roof flashings are indicated in Fig. 21. Before proceeding to fit the flue, ensure that the maximum flue length has not been exceeded (See the tables on Page 24) and that all elbows and bends have been taken into consideration, the maximum flue length is 5 metres, for each additional 90 o elbow 1 metre must be subtracted from the total flue length, and for each 45 o 0.5 metres must be subtracted from the total flue length (the height of the vertical adaptor and a 45 o bend can be seen in Fig. 22). Mark the position of the flue hole in the ceiling and/or roof (see Fig. 21 for distance from wall to the centre of the flue). Cut a 120mm diameter hole through the ceiling and/or roof and fit the flashing plate to the roof. DO NOT cut the vertical flue kit. To connect the vertical flue kit directly to the boiler, place the vertical starter kit (Part No. 3318079) (see Figs. 21 & 22) onto the exhaust manifold and secure with the clamp, fit the vertical adaptor onto the vertical starter kit (note: there is no need to use a clamp to secure this as it is a push fit connection), the vertical flue kit must then be inserted through the roof flashing, this will ensure that the correct clearance above the roof is provided as the terminal is a fixed height. Should extensions be required, they are available in 1 metre (Part No. 3318077), 500mm (Part No. 3318078) and 160mm lengths, they must be connected directly to the vertical starter kit before connecting the adaptor to allow the vertical flue kit to be fitted. In the event that extension pieces need to be shortened, they must only be cut at the male end and it must be ensured that the inner and outer flue remain flush. When utilising the vertical flue system, action must be taken to ensure that the flue is supported adequately to prevent the weight being transferred to the appliance flue connection by using 1 flue bracket per extension. When the flue passes through a ceiling or wooden floor, there must be an air gap of 25mm between any part of the flue system and any combustible material. The use of a ceiling plate will facilitate this. Also when the flue passes from one room to another a fire stop must be fitted to prevent the passage of smoke or fire, irrespective of the structural material through which the flue passes. Fig. 21 Fig. 22 22

12. Connecting the flue (continued) 12.4 Fitting the twin pipe (Ø80/80) NOTE: SEE PAGE 24 FOR MAXIMUM AND MINIMUM FLUE RUNS (TABLE C) Where it is not possible to terminate the flue within the distance permitted for coaxial flues, the twin flue pipe can be used by fitting a special adaptor to the flue connector and using the aperture for the air intake located on top of the combustion chamber. Always ensure that the flue is adequately supported, avoiding low points. (MTS supply suitable clamps as Part No. 705778). To utilise the air intake it is necessary to: 1) Take the air intake cover off; 2) Assemble the flange on the header supplied with the boiler; 3) Insert the restrictor if necessary, on the tube or the elbow; 4) Insert the header on the tube or the elbow up until the lower stop (you do not have to use the washer); 5) Insert the elbow/header in the boiler air intake hole and fasten it with screws; The twin flue pipes can be fitted with or without additional elbows and need no clamps, simply ensure that the red o-ring is inserted in the female end of the flue pipe and push the extension piece fully into the previous section of flue pipe or elbow, check that the o-ring is not dislodged when assembling the flue. Twin pipe can also be converted back to Coaxial flue to enable vertical termination with a coaxial kit by using the pipe bridge (Twin - Coaxial Adaptor - Part No. 705767). When running the twin flue pipe vertically. It is not recommended that the pipe bridge be used for horizontal termination, however in the unlikely event that this proves to be a necessity it is extremely important that the entire flue has a fall of 5mm in every metre back to the boiler, and where the 60mm inner flue of the concentric terminal connects to the pipe bridge, this point must be adequately sealed with silicone sealant to avoid condense leakage at this point. When siting the twin flue pipe, the air intake and exhaust terminals must terminate on the same wall, the centres of the terminals must be a minimum of 280 mm apart and the air intake must not be sited above the exhaust terminal (refer to Fig. 27). The air intake pipe can be run horizontally, however, the terminal and the final 1 metre of flue must be installed with a fall away from the boiler to avoid rain ingress. It is also strongly recommended that the air intake pipe run be constructed of insulated pipe to prevent condense forming on the outside of the tube. The maximum permissible flue length for twin flue is dependent on the type of run used. For flue runs with the intake and exhaust pipes under the same atmospheric conditions (TYPE 4) the maximum length is 60 metres (24kW and 30kW), for runs with the terminals under different atmospheric conditions (TYPE 5) the exhaust terminal must extend 0.5 metres above the ridge of the roof (this is not obligatory if the exhaust and air intake pipes are located on the same side of the building). For TYPE 5 also, the maximum permissible combined length is 60 metres (24kW and 30kW). The maximum length is reached by combining the total lengths of both the air intake and exhaust pipes. Therefore a maximum length of 60 metres for example, will allow a flue run of 30 metres for the air intake and 30 metres for the exhaust pipes, also for each 90 o elbow 2.2 metres must be subtracted from the total length and for each 45 o elbow 1.4 metres must be subtracted from the total flue length. Some of the acceptable flue configurations are detailed on page 25. For further information relating to flue runs not illustrated, please contact the Technical Department on 0870 241 8180. 123.5 141 230 MIN * 132 200 Fig. 23 Fig. 24 23