Operation Manual

34
De Dietrich Gas 310/610 ECO
8.5 Switch sequence diagram
8.6 Boiler control
8.6.1 Gas 310 Introduction, Gas 610 each module
Fig. 19 Switch sequence diagram [04.31H.79.00003]
The De Dietrich Gas 310/610 ECO can be controlled using one of the following methods:
Note: When using on/off control the boiler will also modulate to maintain the flow temp set point
(parameter )
• Fully modulating, where the output
modulates between the minimum and
maximum value on the basis of the flow
temperature defined by the modulating
controller.
• Analog control (0-10 volts), where the
heat output or temperature is controlled
by a 0-10 volt signal.
• On/off control, (one-volt free relay) where
the heat output modulates between the
minimum and maximum value on the
basis of the flow temperature set in the
boiler.
High/low control, (two volt free relays) where the
boiler is controlled by means of a 2-stage
controller at part load and full load.
Fig. 20 °output control characteristic
In all cases, modulation is based on the required flow temperature and there is a

T
dependent output control with
the following characteristic. Up to a

T
of 45°F [25°C] (factory setting, parameter ) the boiler operates at full
output. Between

T full load
and 
T part load
the output reduces in linear fashion (see fig. 20).