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ÜKY/DUO Boiler User Manual
pipes in the system are evacuated by opening the air pipes to the atmosphere from the expansion
tank. It is recommended to use separate expansion tanks for each boiler in the installation, according
to their capacities. So it is not right to connect two boilers to one expansion tank. There are flow and
return safety pipes for each boiler and expansion tank. Valves, check valves etc. on these safety
pipes. No fittings such as material should be installed. The safety pipes should reach the nearest
point of the boiler inlet and outlet from the shortest vertical path. Horizontal movement is permitted
only at the level of the expansion tank and the minimum length.
ÜNMAK DUO series solid fuel boilers must be connected to an installation with an open expansion
tank in accordance with the installation scheme shown below. The circulation pump can be
connected on the flow or return line. In case the pump is at the return of the boiler; open expansion
tank should be higher than the head of the pump.
Warning about water level:
After the first water is pumped into the system, the minimum water level should be marked on the
hydrometer. The water level should be checked daily, and water should be added to the installation
when it falls below the minimum value.
Open expansion tank volumes that should be according to Ünmak boiler power
BOILER POWER
(Mcal/h)
OPEN EXPANSION
TANK VOLUME (lt)
25
50
40
90
60
90
80
110
100
210
Open expansion tanks are selected by assuming Ünmak brand open expansion volumes and panel radiators in the system.
Adding fresh water to the installation should be done only when the installation is cold.
