Frost Protection; Dhw Indirect Water Heater - Baxi LUNA DUO-TEC 1.70 User Manual

NOTICE
All wiring must be NEC Class 1. If any of the originally supplied boiler wiring needs to be replaced, use only wire with
a TEW 105°C or equivalent designation. The boiler has to be electrically grounded as required by the latest National
Electrical Code ANSI/NFPA 70.
Outdoor temperature.
Flow temperature.
P1: Supply temperature (maximum).
P25: Supply temperature (minimum).
P26: WWSD (Warm Weather Shutdown).
P27: Outdoor temperature (default).
If an outdoor temperature sensor is connected, it is possible to adjust the heating curve. The setting can be modified using
parameters P1, P25, P26 and P27.

10.3 FROST PROTECTION

FROST PROTECTION IN
THERMOSTAT
If an on/off thermostat is used, it is recommended to protect any rooms
where there is risk of freezing by using a freeze thermostat; however, the
radiator valve or zone, where there is a risk of freezing, must be open.
• In rooms where there is a risk of freezing, a freeze thermostat (FT)
should preferably be installed.
• Connect the frost thermostat in parallel with an on/off room thermostat
(RT) to the ON/OFF-OT terminals of the control board connection.
NOTICE
When using an OpenTherm thermostat, a freeze thermostat cannot be connected in parallel to the ON/OFF-OT terminals.
Instead, implement frost protection for the heating system using the outdoor temperature sensor.
FROST PROTECTION IN COMBINATION WITH AN OUTDOOR TEMPERATURE SENSOR
The heating system can also be protected against freezing in combination with an outdoor temperature sensor; however, the
radiator valve or zone must be open where there is a risk of freezing. Connect the outdoor temperature sensor to the "T out"
terminals of the control board connection.
The frost protection activates when the outdoor temperature sensor reads a temperature lower than 14ºF/-10ºC (this can be
adjusted using parameter P30) the circulation pump switches on and continuously runs until the outdoor temperature increases
past the value set on parameter P30.

10.4 DHW INDIRECT WATER HEATER

CONNECTING THE DHW INDIRECT WATER HEATER/THERMOSTAT
Connect the DHW indirect tank sensor or thermostat (TS) to the "T dhw"
terminals on the control board connection.
7703477.01 (1-03/18)
COMBINATION WITH AN ON/OFF
FT
On/off
OT
28
RT
TS
BL RL Tout Tdhw