Application's Manual

Data subject to change without notice | 01.2011
BOSCH THERMOTECHNOLOGY CORPORATION
THERM Tankless Water Heater Applications Manual
12
|
Technical Specifi cations continued
Model 660 EF 660 EFO 520 HN 520 PN 330 PN
Gas input
(BTU/hr)
Min: 20,000 Min: 20,000 Min: 30,735 Min: 31,000 Min:
Max: 140,000 Max: 140,000 Max: 117,000 Max: 117,000 Max: 74,900
Minimum fl ow to activate (GPM) 0.5 0.5 0.5 0.5 0.5
Maximum fl ow rate at 35° rise (GPM) 6.6 6.6 5.2 5.2 3.3
Maximum fl ow rate at 90° rise (GPM) 2.6 2.6 2.0 2.0 1.3
Thermal Effi ciency NG: 82%
LP: 82%
NG: 82%
LP: 82%
NG: 80%
LP: 80%
NG: 78%
LP: 78%
NG: 78%
LP: 78%
Dimensions
(inches)
H: 20.5
W: 13.8
D: 6.7
H: 20.5
W: 13.8
D: 6.7
H: 36.75
W: 18.25
D: 10.5
H: 25.79
W: 18.11
D: 8.66
H: 22.83
W: 12.20
D: 8.66
Weight (lbs.) 36 36 35 35 26
Modulating gas valve yes yes no no no
Ignition Electronic Electronic Hydro-
generated
Standing
pilot
Standing
pilot
Gas connection ¾" Male NPT ¾" Male NPT ¾" Male NPT ¾" Male NPT ½" Male NPT
Water connections ¾" Male NPT ¾" Male NPT ½" Male NPT ½" Male NPT ½" Male NPT
NG gas pressure
(inches of W.C.)
Min: 4
Max: 10.5
Min: 4
Max: 10.5
Min: 5.7
Max: 14
Min: 5.7
Max: 14
Min: 5.7
Max: 14
LP gas pressure
(inches of W.C.)
Min: 8
Max: 14
Min: 8
Max: 14
Min: 10.5
Max: 14
Min: 10.5
Max: 14
Min: 10.5
Max: 14
Water pressure
Static - (PSI)
Min: 30
Min (well): 40
Max: 150
Min: 30
Min (well): 40
Max: 150
Min: 30
Min (well): 40
Max: 150
Min: 30
Min (well): 40
Max: 150
Min: 30
Min (well): 40
Max: 150
Electrical supply 120VAC 120VAC N/A N/A N/A
Venting options Fan assisted
Vertical and
horizontal
termination
Outdoor
installation
Vertical
natural draft
* horizontal
termination
only with AQ4
vent kit
Vertical
natural draft
* horizontal
termination
only with AQ4
vent kit
Vertical
natural draft
* horizontal
termination
not allowed
Venting diameter
(inches)
3 N/A 5 5 4
Vent material Stainless steel
(AL29-4C)
N/A Type B-vent
recommended
Type B-vent
recommended
Type B-vent
recommended