SERIES

MODEL
CODE
NATURAL
GAS		 CODE
LPG
ZOOM SERIES
Z 420A
20350 20351
ZF 420A 20352 20353
Z 520A 20354 20355
ZF 520A 20356 20357
ZW 520A 20358 20359
ZWF 520A 20360 20361
ZF 520A Inox 20362 20363


KEY
 PILOT FLAME
NATURAL DRAUGHT
HEATING
 AUTOMATIC
IGNITION
FORCED DRAUGHT
PRODUCTION OF INSTANTANEOUS
SANITARY WATER

FEATURES
- Electronic modulation on both circuits
- Electronic card using microprocessor technology
- Temperature control using NTC probes
- Possibility of "minimum power" adjustment on the heating circuit
- Possibility of "maximum power" adjustment on the heating circuit
- Adjustable re-ignition differential
- Possibility of timing in the heating cycle
- Printed circuit malfunction signal regarding:
heating probe breakdown
hot water probe breakdown
- Antifreeze device activation signal:
system low temperature "warning" threshold
antifreeze program "alarm" threshold
- Heat exchanger overtemperature signal
- External visual signal of operating malfunctions (for the user)
- Light signals showing correct operation by the:
heating circuit
hot water circuit		 - Slow ignition
- Minimum ignition pressure adjustment of the burner
- Heating temperature adjustment
- Hot water temperature adjustment
- Post-circulation pump and fan with anti-scale fvnction
- Pump activation in case of overtemperatures of the heat exchanger
- Pump anti-seizure function every 50 hours
- Light signal showing insufficient water in the heating circuit
- Burner ignition failure signal
- High performance bithermic heat exchanger
- Pressure stabilizer of the gas valve
- Electronic hot water priority flow detector, sensitive at low operating pressures, even lower than 0.1 bar
- Pipeline system water pressure switch
- Thermometer
- Water gauge
- Multigas steel burner
- Automatic relief valve
- 3 bar safety valve
DIMENSIONS OF THE
COMBINATION BOILER
INSTALLED INSIDE THE WALL
THE "CLASSIC"
COMBINATION BOILER
 THE "EXTRA THIN"
COMBINATION BOILER		 WALL
ZW 520A - ZWF 520A

TECHNICAL SPECIFICATIONS
DESCRIPTION UNIT OF MEASURE Z 420A Z 520A
ZW 520A		 ZF 420A ZF 520A
ZWF 520A
Rated heat output (working)
BTU / h - kW
20.167-23,45
 20.200 -23,5
Reduced heat output (working)
 BTU / h - kW 9.288 -10,8 9.632 -11,2
Working thermal efficiency at rated power
 % 90,2 90,4
Working thermal efficiency at 30% of rated power
 % 87,4 88
Max. working pressure of heating circuit
 bar - P.S.I. 3 3
Adjustable temperature in heating mode
 °C 30 - 80 30 - 80
Expansion tank - Total volume
 litri 6 6
Rated heat throughput in sanitary mode
 BTU / h - kW 22.350 - 26 22.350 - 26
Reduced heat throughput in sanitary mode
 BTU / h - kW 9.198 - 10,7 9.198 - 10,7
Rated heat output (working) in sanitary mode
 BTU / h - kW 20.167-23,45 20.315 -23,5
Reduced heat output (working) in sanitary mode
 BTU / h - kW 8.000 - 9,3 8.000 - 9,3
Adjustable temperature in sanitary mode
 °C 35 - 55 35 - 55
Maximum water available with continuos working (t 25° C)
 lt/min - gals/min 13,5 13,5
Specific flow rate (EN 625)
 lt/min - gals/min 11,3 11,3
Minimum sanitary water flow rate
 lt/min - gals/min 2,8 2,8
Minimum/maximum sanitary water pressure
 bar - P.S.I. 0,1 - 7 0,1 - 7
Electrical connection
 V - Hz 230 - 50 230 - 50
Rated absorption
 A 0,5 0,8
Electrical appliance protection
 IP X4 D X4 D
Maximum electricity consumption
 W 90 140
CO2 content (natural gas) "B" type boilers
 % rated reduced 4,8 - 2,7 -----
CO2 content (natural gas) "C" type boilers***
 % rated reduced ----- 5,75 - 2,75
CO2 content (LPG G30) "B-C" type boilers
 % rated reduced 6 - 3,6 6,95 - 3,85
*** With coaxial pipe, max. lenght 3 metres
DIMENSIONS
Widht
 mm 425 500
Height fittings center distance
 mm 673 673
Depth
 mm 290 230
Stack
 .mm 130 130
Net weight
 kg 29 (Z 420A)
28,5 (Z 520A)
24 (ZW 520A)		 36 (ZF 420A)
35 (ZF 520A)
30,5 (ZFW 520A)