AK NO : UGM-AK-03/04
GAS FIRED BOILERS
WITH PAGE : 9
3.5. WATER CIRCULATION SYSTEM
The system design must provide water flow rates commensurate with boiler output and the temperature difference
between flow and return should not exceed 20 C, or 25 C at most.
Water levels should be checked regularly and any leakages corrected in order to keep system water make-up
to a minimum, because excessive make-up will lead to salt deposits forming in the boiler waterways Causing
local overheating and damage to the boiler sections. Where there is doubt as to the quantity of water make-up,
a water meter should be fitted.
Boiler water systems should be thoroughly flushed and cleaned before a new boiler is installed and system water
should be treated by a reputable specialist and best practice observed. Consideration should be given to the fitting
of sludge traps and strainers if site conditions warrant them.
For heating systems with maximum boiler temperature up to 100 C, the necessary water purification shall be in
accordance with VDI 2035:
Boiler capacity range Nr. Requirements at the filling and auxiliary water
100 < Q in kW <350 1No requirement is needed, if content of Calcium
Hydrocarbonate (CA(HC03)) is max 2 mol/m³, and if no
285 more than the triple water filling of the plant does not
# take place
350 < Q in kW <1000 2Like 1, however content of Calcium Hydrocarbonate is
max. 1,5 mol/m³
1000 < Q in kW 3In this case, quantity of water, which can be fed without
softening, is to be determined after VDI 2035 equation
(9). If the system needs more filling and auxiliary water,
this must be demineralized.
The maximum quantity of water Vmax, which can be re-fed without softening as filling and auxiliary water, is
determinable after equation (9) the VDI 2035 sheet 1:
Vmax in m³ =0,0313 x Q in kW
Concentration of (CA(HC03)) in mol/m³
The quality of water is important. The recommended hardness of water: 1-3 mol/m3 (1 mol/m3=5.6 dH), PH:8-9.5
NOTE !
We strictly recommend to use water treatment products in heating system prior to first operation of the boiler. Such
water pre-commission products will protect the heating system against any further attack from corrosion or
limescale, and thus prevent
Boiler noise,
Sticking pumps,
Radiator cold spots,
Unestimatad thermal shocks on boiler sections,
saving energy and extending whole heating circuit operation life.
REVISION
00
Failure to apply and maintain the correct water treatment to prevent the formation of scale and corrosion within the
the heating system will render all appliance warranties null and void.
Murat GEDİK TECHNICAL INFORMATION
PREPARED BY DOCUMENT TYPE VALIDITY DATE END OF VALIDITY
