3.3 PHYSICAL DATA 3.4 FLUE LENGTHS A 500 mm or 1000 mm Easy-Flue terminal kit with 90° bend or horizontal terminal is available. CD 750 mm and 1000 mm flue extensions are available. Length of Flue Required:- Rear Flue = wall thickness + 180 mm (includes terminal). Side Flue = wall thickness + distance between wall and side of boiler + 265 mm (includes terminal). Vertical Flue = distance from top of boiler side panel to required roof position minus 1000 mm for vertical terminal assembly. Maximum horizontal flue length = 12 m. Maximum vertical flue length including terminal is 14 m. Each additional CD 90° Bend is equivalent to 1.3 m of flue length.
Each CD 45° Bend is equivalent to 0.9 m of flue length. The CD Vertical Flue terminal assembly is equivalent to 1 m of flue length. 3.5 PUMP The boiler is equipped with a variable speed low power consumption pump. During the DHW mode, the pump always runs at the maximum speed. During the CH mode, three different functioning modes of the pump are available, Proportional, Fixed and Constant ) T. Proportional - The pump speed is controlled automatically in order to give a proportional pump head, the pump speed varies based on the heat output supplied by the burner - the greater the heat output the higher the pump speed. See parameter A3 in Section 6.13.
It is possible to adjust the pump speed range in the boiler parameter menu. Fixed - The pump runs at a constant speed by setting the same minimum and maximum speeds. See parameters A1 and A2 in Section 6.13. Constant - The pump speed is controlled to give a set ) T. See parameter A3 in Section 6.13. The boiler is factory set to Constant - to achieve a ) T of 15°C (parameter A3 is set to 15) By-pass Regulation - The boiler leaves the factory with the by-pass open. If necessary, the by-pass can be adjusted to the system requirements from maximum (by-pass open) to minimum (by-pass closed). Adjust using a flat head screwdriver, turn anticlockwise to close the by-pass, and clockwise to open.
With the by-pass in the closed position the system must have a continuous open circuit. If zone valves are used in the system an external by-pass must be fitted.
6 Alpha E-Tec 28 and 33 - Technical Data Boiler flow and return connections mm 22 DHW inlet (cold) DHW outlet (hot) connections mm 15 Gas connection diameter mm 22 Boiler dimensions Height mm 712 Width mm 440 Depth mm 268 Clearances for servicing Bottom mm 150 Bottom (with jig) mm 250 Top (horizontal flue) mm 235 Top (vertical flue) mm 150 Sides mm 5 Front mm 450 Recommended hole size for flue pipe mm 110 Recommended hole size for instalation from inside the building mm 130 Boiler dry lift weight E-Tec 28 kg 33.6 E-Tec 33 kg 35.5 Boiler operating weight (full of water) approx. E-Tec 28 kg 35.8 E-Tec 33 kg 37.9 Max. total flue length Horizontal m 12 Max.
total flue length Vertical m 14 Flue system diameter mm 60/100 Ambient operating temperature °C 5 min. 40 max.