Heating engineer
Installation, use and maintenance manual – K18 Simplygas
27
3
caused by improper glycol use.
Always check product suitability and its expiry date with
the glycol supplier. Periodically check the product's pres-
ervation state.
Do not use car-grade antifreeze liquid (without inhibi-
tors), nor zinc-coated piping and fittings (incompatible
with glycol).
Glycol modifies the physical properties of water (densi-
ty, viscosity, specific heat...). Size the piping, circulation
pump and thermal generators accordingly.
With automatic system water filling, a periodic check of
the glycol content is required.
With high glycol percentage (> 20…30%)
If the glycol percentage is ≥30% (for ethylene glycol) or
≥20% (for propylene glycol) the TAC must be alerted be-
fore first start-up.
When producing DHW by DHW buffer tank, use pro-
pylene glycol only.
3.7.1
Type of antifreeze glycol
Inhibited type glycol is recommended to prevent oxidation
phenomena.
3.7.2
Glycol effects
The Table 3.1
p. 27 shows, indicatively, the effects of using a
glycol depending on its %.
Table 3.1
Technical data for filling the hydraulic circuit
Glycol %
Water-glycol mixture freezing
temperature
Percentage of increase in pressure drops
Loss of efficiency of unit
10
-3 °C
-
-
15
-5 °C
6,0%
0,5%
20
-8 °C
8,0%
1,0%
25
-12 °C
10,0%
2,0%
30
-15 °C
12,0%
2,5%
35
-20 °C
14,0%
3,0%
40
-25 °C
16,0%
4,0%
3.8
SYSTEM WATER QUALITY
Responsibility of the user/operator/installer
The installer, operator and user must assure system wa-
ter quality (Table 3.2
p. 27). Failure to comply with the
manufacturer's guidelines may affect operation, integri-
ty and life of the appliance, voiding the warranty.
3.8.1
System water characteristics
Free chlorine or water hardness may damage the appliance.
Adhere to the chemical-physical parameters in Table 3.2
and the regulations on water treatment for residential and in-
dustrial heating systems.
Table 3.2
Chemical and physical parameters of water
Chemical and physical parameters of water in heating/cooling systems
Parameter
Measurement unit
Required value
pH
/
> 7 (1)
Chlorides
mg/l
< 125 (2)
Total hardness (CaCO
3
)
°f
< 15
°d
< 8,4
Iron
mg/kg
< 0,5 (3)
Copper
mg/kg
< 0,1 (3)
Aluminium
mg/l
< 1
Langelier’s index
/
0-0,4
Harmful substances
Free chlorine
mg/l
< 0,2 (3)
Fluorides
mg/l
< 1
Sulphides
ABSENT
1
With aluminium or light alloys radiators, pH must also be lower than 8 (in compliance
with applicable rules)
2
Value referred to the maximum water temperature of 80 °C
3
In compliance with applicable rules
3.8.2
Water topping up
The chemical-physical properties of the system's water may alter
over time, resulting in poor operation or excessive topping up.
▶
Ensure there are no leaks in the installation.
▶
Periodically check the chemical-physical parameters of the
water, particularly in case of automatic topping up.
Chemical conditioning and washing
Water treatment/conditioning or system washing car-
ried out carelessly may result in risks for the appliance,
the system, the environment and health.
Contact specialised firms or professionals for water treat-
ment or system washing.
Check compatibility of treatment or washing products
with operating conditions.
Do not use aggressive substances for stainless steel or
copper.
Do not leave washing residues.
Always refer to the requirements of the standards and
existing regulations.
3.9
SYSTEM FILLING
After completing all water, electrical and gas connections:
1. Pressurise (at least 1.5 bar) and vent the hydraulic circuit.
2. Make sure that the unit is energized.
3. Send an operating request to the unit for a few seconds. The
circulating pump will be immediately activated.
4. Remove the request before the burner is activated. The cir-
culating pump will continue to circulate the water for the
post-circulation time.
5. Check and clean the filter on the inlet pipe.
6. Repeat items 1, 2 and 3 until the pressure has stabilised (at
least 1.5 bar).
