6.3
Check the water level in the heating circuit
The system pressure of the installation must be checked once a month. The external manometer must show a
value between 1-1.5 bar. If the value is below 0.8 bar when the water in the heating system is cold, the water
must be topped up (applies to unvented systems). You can use normal tap water when topping up the heating
system. In certain exceptional cases the water chemistry may be so poor (for example very hard water) that it is
not suitable for filling the heating system. If you are unsure, contact your installer.
N
Do not use any additives for treatment of the water in the heating system.
N
The unvented expansion vessel contains an air-filled bladder that absorbs var-
iations in the heating system’s volume. Under no circumstances may it be
drained of air.
6.4
Check the brine circuit level
The brine circuit must be filled with the correct amount of fluid otherwise operational interruptions may occur.
The brine must be topped up when the level drops so that it is no longer visible in the expansion tank.
1
2
1
Correct level
2
Level too low
During the first month of operation the brine level might drop slightly; this is quite normal. The fluid level may
also vary depending on the temperature of the heat source. Under no circumstances must the fluid level be
allowed to drop so far that it is no longer visible in the expansion tank.
For Atria with pressurised brine circuit, the manometer on the expansion tank must show approximately 1.0
bar.
Always call your installer if the brine requires refilling.
User Guide
Domestic heat pumps
Thermia Värmepumpar
VUGFD202
19
