Recirculation Pump; Adjusting The Door; For Models Prextherm Rsw 92N÷600N(Fig. 9); For Models Prextherm Rsw 720N÷1060N (Fig. 10) - Ferroli PREXTHERM RSW 92N Instructions D'utilisation, D'installation Et De Montage

5.5.5 Recirculation pump

Condensation ºof the water vapor contained in the flue gas leaving the boiler (conden-
sate) occurs when the return water temperature is below 50ºC. This is significant,
particularly when the boiler is turned on in the morning after being off all night. Con-
densate is acidic and corrosive, and will damage the metal plating on the boiler over
time. It is therefore advisable to install a recirculation pump with an anti-condensa-
tion feature, to be fitted between the feed and return fittings, upstream of any mixing
valve. While the system is operating, the pump must ensure a flow-rate of 20 to 30%
of the total. The (anti-condensation) recirculation pump is controlled using the
Low-Temperature Thermostat Panel (optional). The bulb for the corresponding ther-
mostat must be fitted at the return (using a sheath that must be added by the installer
of that pipe).

5.6 Adjusting the door

5.6.1 For models PREXTHERM RSW 92N÷600N(Fig. 9)
Opening
The burner door can be opened to the right or left. Simply loosen nuts 1 on the right
or left.
Horizontal tightness and adjustment
Rotate both lock nuts 2, tighten nuts 1 as needed, and lock both lock nuts 2.
Vertical positioning and adjustment
After assembling the burner, it may be necessary to reposition the door. To do so,
loosen nuts 1, loosen set screws 3, and adjust with nuts 4.
Tighten nuts 1 to completely flatten seal 5.
After installing the burner, the door must be positioned. This can be done by loose-
ning nuts 1 and 3 and set screw 5, and using nut 6 to adjust the height. This must
be done so that the entire rope seal presses against the plate, by tightening nuts 1
and 3.
5.6.2 For models PREXTHERM RSW 720N÷1060N (Fig. 10)
On all pressurized boilers, it's possible to adjust and reverse the side where the door
opens.
Opening
To set the side of the door, simply tighten lock nuts 2 and 4 against nuts 1 and 3.
To reverse the side where the door opens, tighten lock nuts 2 and 4 on the opposite
side.
Closing
Loosen lock nuts 2 and 4, tighten nuts 1 and 3 as needed, and retighten lock nuts
2 and 4.
Positioning
After installing the burner, the door must be positioned. This can be done by loose-
ning nuts 1 and 3 and set screw 5, and regular in height with the nut 6.
It will be necessary to do it in such a way that the whole closing cord presses on the
sheet, tightening the nuts 1 and 3.

5.7 Montaje del quemador (Fig. 11)

The assembly of the burner at the boiler door must ensure perfect tightness for the
products of combustion. Once the burner is installed on the boiler, the space between
the burner nozzle and the refractory material on the door must be filled with the cera-
mic fiber padding (A) provided.
This prevents the door from overheating, which would result in irreversible warping.
44 EN
PREXTHERM RSW N
fi g.8
fi g.9
6
5
2
1
4
3
fi g.10
A73020801