6 720 607 072
4
Appliance details
2 Appliance details
2.1 Features
Parts
• Touch Pad interface control
• High power pre-mix compact burner with low Nox
emissions
• Modulating Gas Valve with constant gas:air ratio
control
• Modulating water v alve for improved comfort and
temperature control.
Safety
• Flame sensor (ionization) rod
• Overheat sensor
• Temperature limiter
• Fan speed monitoring.
High Quality Materials for Long Working Life
• Copper heat exchanger
• High efficiency Ceramat Burner
• Compact space saver: mounts on a wall with a
supplied bracket.
• Easily removable one-piece cover.
Features
• LCD Display
• On/Off and Temperature control switches
• Reset button
• Program Key (Selectable temperature default)
• Failure codes for easy diagnostic and repair.
Accessories
• Optional wireless remote control accessory to
operate with the appliance
• Vent termination kit.
2.2 GWH-635-ES Specifications
(Technical data)
Approved in US/Canada
Capacity
Maximum flow rate: 6.35 GPM (24 l/min) at a 45°F
(25°C) rise.
Maximum output
142,968 Btu/h (41.8 kW)
Maximum input
175,000 Btu/h (51.2 kW)
Efficiency in %
Recovery efficiency 86.5%
Min. Output
31,131 Btu/h (9.1 kW)
Temperature Control
Selection range: 100°F (38°C) - 140°F (60°C)
Default temperature: 122°F (50°C)
Stability: +/- 2°F (+/- 1°C)
Gas Requirement
Gas connection (inches) - ¾”
Inlet g as pressure under operation (with a high hot
water flow rate)*
• Propane: 11” - 14” water column
• Natural Gas: 5” - 14” water column.
* To measure Gas Pressure, see Measuring Gas
Pressure, chapter 2.12.
Venting
A condensate trap is integrated into the exhaust flue
gas collar of the heater, the supplied condensate drain
tube must be installed to it for proper remova l of
condensate from the trap. See chapter 2.9 for Venting.
Water
• Hot water connection (inches) - ¾”
• Cold water connection (inches) - ¾”
• Water valve material: Polymer (PPS) (Polypropylene
Sulfid)
• Minimum water flow: 0.8 gallon/minute (3 l/m)
• Minimum recommended water pressure: 30 PSI
(2.07 bar)
• Connections:
– Bottom of heater
i
BOSCH is constantly improving its
products, therefore specifications are
subject to change without prior notice.