Unit installation
User, Installation and Service Manual for F1 Gas Unit Heaters  11
Ed. 05/2009 
Note:  When horizontal pipes with lengths above 1 metre are installed, the flue pipe must be 
mounted with a slope of 2 to 3 cm each 1 metre length (see fig. 5), to prevent entering the 
condense drops into the unit. In addition, to install correctly the flue exhaust and the air intake 
terminals, follow the details given in figure 8. 
SLOPE
2-3 CM PER METER
Figure 5 
SLOPE OF THE HORIZONTAL FLUE PIPE 
Note: 
When vertical pipes with length above 3 metres are installed, to prevent that condense drops 
enter the unit, on base of the vertically mounted flue pipe a T-shaped piece MUST be fitted, 
in order to collect the condense. 
Figure 6   Figure 7 
INSTALLATION TYPE B23 WITH WALL TERMINAL    INSTALLATION TYPE B23 WITH ROOF TERMINAL 
FLUE
AIR 
TOP VIEW 
SIDE VIEW 










