Heating Circuit - Viessmann Vitocrossal 300 CA3 2.5 Installation And Service Instructions Manual

Vitocrossal 300 CA3 Series 2.5 to 6.0 Installation/Service
"Solar" Group
(continued)
Coding in the factory set condition
"Extended control function"
20:0 No extended control function enabled.
"Heating Circuit ..." Group
Coding
Coding in the factory set condition
"Storage tank priority"
a2:2 Tank priority control for heating circuit
pump and mixing valve.
"Heating circuit pump logic function (economy control)"
a5:5 With heating circuit pump logic function
(economy control): heating circuit pump
OFF when the outdoor temperature (OT)
is 2°F (1 K) higher than the set room
temperature (RTset) OT > RTset +2°F
(1 K).
Coding address With heating circuit pump logic function:
a5:... Heating circ pump OFF
1 OT > RTset +9°F (+ 5 K)
2 OT > RTset +7°F (+ 4 K)
3 OT > RTset +5°F (+ 3 K)
4 OT > RTset +4°F (+ 2 K)
5 OT > RTset +2°F (+ 1 K)
6 OT > RTset
7 OT > RTset –2°F (– 1 K)
to
15 OT > RTset –16°F (– 9 K)
Possible change
20:1 Additional function for DHW heating.
20:2 Differential temperature control 2.
20:3 Differential temperature control 2 and auxiliary
function.
20:4 Differential temperature control 2 for central
heating backup.
20:5 Thermostat function
20:6 Thermostat function and auxiliary function.
20:7 Solar heating via external heat exchanger
without additional temperature sensor.
20:8 Solar heating via external heat exchanger with
additional temperature sensor.
20:9 Solar heating of two DHW storage tanks.
Possible change
a2:0 Without storage tank priority applicable
to heating circuit pump and mixing valve.
a2:1 Storage tank priority only applicable to
mixing valve.
a2:3 Modulating priority applies to mixing
to valves, i.e. the heating circuit receives
a2:15 a reduced amount of heat.
a5:0 Without heating circuit pump logic
function.
a5:1 With heating circuit pump logic function:
to Heating circuit pump OFF, see the
a5:15 following table.
Coding Level 1
143