Potterton SIRIUS FS Installation & Servicing Instructions Manual page 37

5.5.5 Combustion Air - General conditions
There must be sufficient clearance around the boiler to allow proper circulation of
combustion air. The clearances required for Installation and servicing will normally be
adequate. (See section 4.2.1)
Combustion air must avoid contents including (but not limited to) chlorine, ammonia,
alkali agents, halogenated hydrocarbons, freon, sheetrock particles, plasterboard
particles, lint dirt and dust. Installation of the boiler near a swimming pool, washing
machine or a laundry do expose combustion air to these contents.
The effect of any type of extract fan in the plant room must be considered and
an additional air inlet may be needed from outside to counter the effect of any
such fans.
5.5.6 Maximum Flue Lengths
The overall resistance of the combined flue pipe work and flue terminal must not exceed a
pressure drop of:
Model
Max flue resistance
Each flue accessory such as bends and straight lengths restrict the flue system and
decrease the boilers output. To ensure that the output of the boiler matches the
approved rating on the data plate please do not exceed these values.
The effect of pressure resistance of the flue system on the output of the boiler is given
in the following table:
Sirius FS
Jug 555 Jug 400
0 500 380
0 50 100
50 494 375
520
100 488 370
150 482 365
500
200 476 360
250 470 355
300 464 350
480
350 458 345
460
440
420
400
380
360
340
320
FS400
200 Pa
Flue resistance (Pa)
150 200 250
FS525
FS400
35
FS525
250 Pa
300 350
GB/IE