19
4.4. S Coil connection (optional)
In the unit there can be an extra heat exchanger installed. In the sensor pocket for the
thermostat sensor, there can also be placed a sensor to control the external connec-
tion e.g. oil burner, wood burner etc. The maximum inlet temperature of the heating
coil is 90 °C. If there is risk of inlet temperatures above 90 °C the installer must install
an external device preventing high inlets temperature to the heating coil.
4.5. Safety instructions – Water circuit
• Only drinking water must be used.
• During installation, attention must be paid to the choice of materials and it must be
ensured that chosen materials work together without problems in the entire cir-
cuit.
• Special attention must be paid when using galvanized components and components
containing aluminum.
• Safety equipment must be installed to prevent over pressure in the system. Always
use a safety valve with maximum relief pressure according to the unit nameplate
and a stop valve (approved according to heating and plumbing regulations). All pipe
work has to be installed according to plumbing and heating regulations.
• The discharge pipe of the pressure-relief device (safety valve) must be installed
frost free and with a slope away from the device. The pipe must also be left open to
the atmosphere.
• Temperatures above 90 °C in the heating coil may cause excessive pressures in the
cooling circuit.
Figure 12 - Condensate drain
