Riello 40 Installation, Use And Maintenance Instructions page 36

ECONOMIZER
This economizer can be wired to 2
to an external probe.
The economizer, connected to the 2
stat, performs two functions:
1. Delay of 5 - 6 seconds in the intervention of the 2
stage valve against 1
2. In relation of the position of the plug B, it determines
the type of required operation:
B
II - I I
II
II - I I
II
II - I I
II
NOTE
In this case the setting screw A is not necessary.
Should the economizer be connected to an external probe, the operation at 1
will be related to the external temperature.
When the external temperature is higher than the fixed value the economizer permits the burner
st
operation only at 1
with the fixed value, the economizer permits the burner operation only at 2
The external temperature causing the economizer intervention might be chosen between –5 °C
and + 10 °C, turning the setting screw A using the screw-driver.
For this type of operation the plug B has to placed in the position I - II .
When the plug B is in the position II or I, the burner operates as previously indicated.
1716
nd
stage thermostat or
nd
stage thermo-
st
stage valve.
Position I - II = Burner operation in 1
Position II
Position I
stage; on the contrary when the external temperature decreases in relation
nd
nd
of the 2 stage thermostat.
= Burner operation only in 2
= Burner operation only in 1
11 GB
S7341
st nd
or 2 stage on request
nd
stage - compulsorily.
st
stage - compulsorily.
st
or 2
nd
stage.
nd
stage