Daikin ETBH16E9W Installer's Reference Manual page 219

Bivalent
EPRA14~18D + ETBH/X16E
Daikin Altherma 3 H HT W
4P644736-1D – 2023.10
Bivalent
Only applicable in case of auxiliary boiler.
INFORMATION
Bivalent is only possible in case of 1 leaving water temperature zone with:
▪
room thermostat control, OR
▪
external room thermostat control.
About bivalent
The purpose of this function is to determine which heating source can/will provide
the space heating, either the heat pump system or the auxiliary boiler.
# Code
[9.C.1] [C-02]
▪ If Bivalent is enabled: When the outdoor temperature drops below the
bivalent ON temperature (fixed or variable based on energy prices), the space
heating by the heat pump stops automatically and the permission signal for the
auxiliary boiler is active.
▪ If Bivalent is disabled: Space heating is only done by the heat pump within the
operation range. The permission signal for the auxiliary boiler is always inactive.
The switch-over between the heat pump system and the auxiliary boiler is based
on the following settings:
▪ [C‑03] and [C‑04]
▪ Electricity price: [7.5.1], [7.5.2], [7.5.3]
▪ Gas price: [7.6]
[C‑03], [C‑04], and T
calc
Based on the settings above, the heat pump system calculates a value T
variable between [C‑03] and [C‑03]+[C‑04].
3°C
a
b
T [C-03]+[C-04]
[C-03]
calc
T Outdoor temperature
A
T Bivalent ON temperature (variable). Below this temperature, the auxiliary boiler will
calc
always be ON. T
3°C Fixed hysteresis to prevent too much switching between heat pump system and
auxiliary boiler
a Auxiliary boiler active
Bivalent: Indicates if the space heating is also
performed by means of another heat source than
the system.
▪ 0 No: Not installed
▪ 1 Yes: Installed. The auxiliary boiler (gas boiler,
oil burner) will operate in space heating when
the outdoor ambient temperature is low.
During bivalent operation, the heat pump will
run in domestic hot water operation when tank
heat-up is required, or is turned OFF. Set this
value in case an auxiliary boiler is used.
T
A
can never go below [C‑03] or above [C‑03]+[C‑04].
calc
10 Configuration
|
Description
, which is
calc
Installer reference guide
219