21
THERM 90 KD.A
3.5 Connecting the boiler to the hot-water system
The boilers must be connected to the heating system in such a manner that the power fittings do not stress the connecting
outlets of the boiler and there is no aeration.
As it concerns a heat-water flow boiler fitted with its own pump, it is necessary to resolve the connection to the heating system
in relation to the calculations of the hydraulic relations of the whole system. Due to the optimal use of the condensing regime
of the boiler, it is recommended to design heating systems for low temperatures (Δt = 50/30 °C). The minimum overpressure
of the system is 0.8 bar. We recommend using the pressure of the heating water in the system within the range 1.0 – 1.5 bar.
3.5.1 Dimensions and connection
BOILER CONNECTION
BOILER MODEL
UNIT
TYPE OF
THREAD
90 KD.A
Input for returned water
G 6/4“
outside
1
Output for heating water
G 6/4“
outside
3
Input for gas
G 5/4“
outside
2
Condensate outlet
5
Output safety valve
4
A
A
1
2
8
3
4
5
6
7
530
975
3x130
60
ŘEZ A-A
500
970
530
230
120
1
2
3
165
80
312
135
115
5
4
50
240
500
970
530
230
120
110/160
