Temperature (Combi); Extinguishing - Biasi RIVA PLUS M90D.24S User Manual And Installation Instructions

Instructions for use
Adjustment
In order to achieve optimal settings for economy
and comfort, we recommend adjusting the oper-
ating temperature of the c.h. water according to
the outside temperature, positioning the knob as
follows:
From 5 to 15 ûC
Fig. 2.8
Your qualified installer will be able to recommend
the most suitable adjustment for your system.
The temperature and pressure gauge (4, Fig. 1.3
on page 1) will allow you to check that the set tem-
perature is obtained.
2.5 D.h.w. temperature (combi)
The temperature of the d.h.w. leaving the boiler
can be varied from a minimum of about 35°C to a
maximum of about 55°C (Fig. 2.9), by turning the
temperature control knob 9.
Minimum
Maximum
Fig. 2.9
Adjustment of the d.h.w. temperature is complete-
ly separate from that of the c.h. circuit.
The adjustment system integrated within the
boiler automatically controls the flow of gas to the
burner in order to keep the temperature of d.h.w.
delivered constant, between the limits of maxi-
mum and minimum output.
Where the demand is at a low level or with the tem-
perature set to the minimum, it is normal to see a
Between
cycle of lighting and extinguishing of the burner
--- 5 and +5 ûC
when running.
Adjustment
It is advisable to adjust the d.h.w. temperature to
a level commensurate with the demand, minimis-
ing the need to mix with cold water. In this way, the
automatic control facilities will be fully exploited.
Lower than
--- 5 ûC
Moreover, where the amount of limescale present
in the water may be particularly great, not exceed-
ing the position in Fig. 2.10 of the d.h.w. tempera-
ture control knob 9 corresponding to about 50°C
(Fig. 2.10), minimises annoying incidences of
scale deposits and clogging.
Fig. 2.10
In these cases, however, it is advisable to install a
small water treatment device or softener. With
such a device you should avoid periodic descal-
ing.
Consequently, the d.h.w. heat exchanger will keep
9
its performance consistent for a longer period of
time with resulting gas savings.
If the demand for d.h.w. is so great as to prevent
reaching a high enough temperature, have the ap-
propriate output limiting valve installed by your in-
staller or an Authorised Service Engineer.
To turn the boiler off set the function selector 8 to
the position shown in Fig. 2.11 (combi) or
Fig. 2.12 (c.h. only).
2.6

Extinguishing

9
5