Bosch Installation Manual

Product Description
Greenstar – 6721822579 (2021/01)
18
3.11 Technical data ZBR...-3A
Table 3 Technical data ZBR 21-3 A...
ZBR 21-3 A...
Input/Output Unit NG LPG (propane)
Max. input rate 180/79 °F (82/26 °C) BTU/hr (kW) 79,200 (23.2) 77,500 (22.7)
Max. output rate 104/86 °F (40/30 °C) BTU/hr (kW) 74,700 (21.9) 74,700 (21.9)
Max. output rate 122/86 °F (50/30 °C) BTU/hr (kW) 74,000 (21.7) 74,000 (21.7)
Max. output rate 176/140 °F (80/60 °C) BTU/hr (kW) 70,300 (20.6) 70,300 (20.6)
Min. input rate 180/79 °F (82/26 °C) BTU/hr (kW) 24,600 (7.2) 40,100 (11.7)
Min. output rate 104/86 °F (40/30 °C) BTU/hr (kW) 23,900 (7.0) 39,900 (11.7)
Min. output rate 122/86 °F (50/30 °C) BTU/hr (kW) 23,900 (7.0) 39,600 (11.6)
Min. output rate 176/140 °F (80/60 °C) BTU/hr (kW) 21,800 (6.4) 36,200 (10.6)
Gas connection value
Natural Gas – H
s
= 1,010 BTU/ft
3
(37.3 MJ/m
3
) ft
3
/hr (m
3
/h) 78 (2.2) –
Liquid Propane Gas – H
D-S
= 2,500 BTU/ft
3
(93.1 MJ/m
3
)ft
3
/hr (m
3
/h) – 31 (0.9)
Permissible inlet gas pressure
NG in. W.C. (mbar) 3.5-10.5"
(8.7-26.1)
–
LPG (propane) in. W.C. (mbar) – 8-13" (19.9-32.3)
Flue gas
Flue gas mass flow at maximum/minimum nominal output
g/s
9.4/3.2 9.2/4.8
Flue gas temperature 176/140 °F (80/60 °C) at maximum/minimum nominal heat
input
°F ( °C) 145/133 (63/56) 145/133 (63/56)
Flue gas temperature 104/86 °F (40/30 °C) at maximum/minimum nominal heat
input
°F ( °C) 115/90 (46/32) 115/90 (46/32)
CO
2
at max. nominal output % 9.4 11.0
CO
2
at minimum nominal output % 8.6 10.4
Condensate
Max. condensate quantity (t
R
= 86 °F (30 °C)) gph (l/h) 0.5 (1.8) 0.5 (1.8)
pH level, approx. 4.8 4.8
General
Voltage V AC 120 120
Frequency Hz 60 60
Max. power consumption (central heating mode) W 205 205
Max. power consumption (Stand-by) W <6 <6
Sound pressure level dB(A) ≤ 39 ≤ 39
Max. supply temperature °F ( °C) 187 (86) 187 (86)
Max. permissible operating pressure (P
MS
) heating psi (bar) 30 (2.07) 30 (2.07)
Permissible ambient temperature °F ( °C) 32 - 122 (0 - 50) 32 - 122 (0 - 50)
Nominal water capacity (heating) gal (l) 0.925 (3.5) 0.925 (3.5)
Weight (without packaging) lbs. (kg) 103.6 (47) 103.6 (47)
Dimensions, W x H x D inch
(mm)
17-21/64" × 33-15/32"13-57/64"
(440 × 850 × 353)