Bosch C1210ES Instructions for use

THERM Tankless Water Heaters
Applications Manual

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THERM Tankless Water Heater Applications Manual
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THERM Tankless Water Heater Applications Manual | 3
Table of Contents
1 Introduction 4
2 Bosch THERM Model Certifications 4
3 Tankless Water Heater Accessories 5
4 Water Quality 6
5 Pump Sizing 7
5.1 Pressure drop curves 7
5.2 Domestic hot water circulation 8
5.3 Tank loading 8
6 Water Heater Sizing & Specifications 9
6.1 Sizing tankless water heaters 9
6.2 Bosch tankless water heater specifications 11
7 Outdoor Installation 13
8 Domestic Water Heating Applications 14
8.1 Low volume applications 15
8.2 Whole house applications 16
9 High Volume Potable Water Heating 20
9.1 Cascading unit applications 20
9.2 Parallel unit applications 23
10 Residential Solar Applications 24
10.1 Tankloading 24
10.2 Booster applications 25
11 Commercial Solar Applications 27
12 Commercial Water Heating Applications 28
12.1 Commercial kitchen applications 28
12.2 Basic tank loading with domestic recirculation 30
12.3 Advanced tank loading commercial hot water system 31

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1 Introduction
This Applications Manual is intended to present some of the most
common applications of the Bosch Therm tankless water heaters.
Application drawings are shown with both piping and corresponding
electrical schematics where applicable. Auxiliary equipment
depicted does not necessarily represent any one manufacturer or
specific model number. There are a wide variety of techniques,
practices and piping strategies possible when installing water
heating appliances. It is the responsibility of the installing contrac-
tor to determine the most suitable arrangement for the application.
All drawings are conceptual in nature and does not address
all design, installation or safety considerations. Additional
safety and/or auxiliary equipment may be needed.
Drawings are for reference use by officials, designers and
licensed installers. It is expected that installers have
adequate knowledge of accepted industry practices for the
equipment, procedures, and applications involved. It is the
responsibiltiy of the installer to ensure that the installation
is in accordance with local building codes.
Although this manual covers many common applications for our
products, system possibilities are virtually endless. Should you
encounter an application that is not covered in this manual or have
any questions regarding any of its content, we encourage you to
contact your local sales representative or us directly at Bosch
Thermotechnology .
This manual is not a substitute for any of the product’s installation
manuals. All specifications subject to change.
Installation must conform with local codes or, in the
absence of local codes, the National Fuel Gas Code ANSI
Z223.1/NFPA 54.
In Canada: Installation must conform with CGA B149.(1,2)
INSTALLATION CODES and/or local installation codes.
2 Bosch THERM Model Certifications
The following are certification stamps and explanations that are
specific to one or more Bosch tankless water heaters. These
certifications bring the appliances in accordance with the
requirements of the National Fuel Gas Code ANSI Z223.1/NFPA 54.
Certified to applicable U.S. standards for
appliances using gas or other petroleum fuel.
Certified to applicable Canadian standards for
appliances using gas or other petroleum fuel.
Certified by Underwriters Laboratories Inc.
Energy efficiency certified by Gas
Appliance Manufacturers Association
(GAMA), www.gamanet.org
For Models GWH C 920 ESC and C 1210 ESC only.
These models are built in accordance with the
requirements of the ASME Boiler and Pressure
Vessel Code and received the Certificate of
Authorization from the National Board. The heat
exchanger has the NB and the HLW stamps.
Plumbing-Heating-Cooling Contractors
Association
Other certifications:
Met the California Energy Commission (CEC) standards
Approved by the Commonwealth of Massachusetts
South Coast Air Quality Management

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3 Tankless Water Heater Accessories
Available accessories Table 1
C 1210 ES/
C 1210 ESC C 1050 ES 940 ESO 940 ES 830 ES
Concentric Vent/air Intake kit - stainless steel
(part# ESHCK)√√
Concentric termination kit - PVC
(part# 196016)√√
Exhaust / intake bird screen
(part# L2594)√√ √√
Vertical vent kit
(part# ESVVT)√√
Horizontal vent kit
(part# 4TWHVK3SII)√√
Outdoor kit
(part# BTOK)√√ √√
Wireless remote control
(part# TSTAT2)√√√√√
Cascading kit
(part# 77090003962)√√√√√
External water filter
(part# 8703305356)√√√√√
Gas conversion kit
(part# 8719002176)√√√√√
Pipe cover
(part# PTPCES)√√ √√
High temp kit
(part# 7736500074)√√√√
Recess box kit
(part# 7736500043)√√√√√
Pressure relief valve
(part# FWL-2)√√√√√
PVC Condensate drain tee
(part# 196061)* √√
Condensate neutralization cartridge kit
(part# JM-2KIT)√√
* Also included in the Concentric termination kit (part# 196016)

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Available accessories continued Table 2
660 EF 660 EFO 520 HN 520 PN 330 PN
Pipe cover
(part# BPCKIT)√√
Remote control - for U.S.A
(part# BRC01US) √√
Remote control - for Canada
(part# BRC01CA) √√
Remote controller outdoor junction box
(part# BOJB) √√
Remote controller cord 10ft (3m)
(part# BRC10CORD) √√
Remote controller cord 26ft (8m)
(part# BRC26CORD) √√
Isolation valves - pressure relief valve included
(part# 9260LA)√√
Pressure relief valve
(part# FWL-2)√√√√√
Freeze prevention kit
(part# (7709003775) √√
4 Water Quality
Poor water quality will have an impact on appliance longevity and
may void the manufacturer’s warranty. For water analysis data call
your local water department, or if on a well, have well water
analyzed periodically. If water quality exceeds one or more of the
values specified below, Bosch recommends consulting a local water
treatment professional for water softening/conditioning options.
Water quality max. levels Table 3
Description Max. Levels
pH pH 6.5 - 8.5
TDS (Total Dissolved Solids) mg/l or ppm 500
Total hardness mg/l or ppm 100 (6 grains)
Aluminum mg/l or ppm 2.0
Chlorides mg/l or ppm 250
Copper mg/l or ppm 1.0
Iron mg/l or ppm 0.3
Manganese mg/l or ppm 0.05
Zinc mg/l or ppm 5.0

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5 Pump sizing
The following section outlines sizing pumps for domestic hot water
circulation and tank loading. Only models approved for such
applications are listed in this section.
Pump must be bronze or stainless steel.
Size the pump according to the system pressure drop chart
below.
Maximum flow allowed through the recirc loop is 5 GPM.
If the water heater is used within an approved hot water
recirculation application and supplied with circulated
water, the heat exchanger warranty is decreased. Please
refer to the installation manual for detailed warranty
period information.
Run the system for 30 minutes to remove debris from the
plumbing. Then remove the unit‘s inlet water filter to
decrease pressure drop through the system.
If the inlet water filter, when removed, contains debris
install a Y-strainer (installer supplied) on the cold water
inlet.
5.1 Pressure drop curves
0
10
20
30
40
50
60
70
0.50.40.30.20.10.0
Flow
(
GPM
)
Pressure (Feet of Head)
C 800 ES,
C 1050 ES
C 920 series,
C 1210 series
2400 ES,
2700 ES,
GWH 715 ES,
830 ES,
940ES/ESO
660 EF/EFO

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5.2 Domestic hot water circulation
 Must provide a recirculation flow above 1.7 GPM. This can be
verified in the control unit diagnostics section of the installation
manual; mode P4 – 3d.
Note: The Grundfos model 15-55 has been tested and shown to
work on recirculating systems up to 120 feet of total pipe length.
System conditions vary and each pump must be sized by a profes-
sional to insure performance.
Refer to pump manufacturers flow vs pressure specifications to
select a pump that can provide the flow rate greater than 1.7 gpm
while overcoming the pressure loss through:
• Tankless water heater (see Chapter 6.1)
• All building supply and return plumbing in the circulation loop
(reference local plumbing codes, standards, or practices)
System pressure drop
Pressure drop ¾" copper (PSI)
90 degree elbow 0.088
45 degree elbow 0.053
10 ft of straight pipe ½" 1.3
10 ft of straight pipe ¾" 0.35
Source: International Plumbing Code 2003 edition.
Examples:
1) Average house (less than 2500 square feet)
a) Total loop length approximately 120 ft
b) Pump recommendation: Grundfos UP 15-55 or equivalent.
2) Large house (2500 to 5000 square feet)
a) Total loop length approximately 240 ft
b) Pump recommendation: Grundfos UP 25-64 or equivalent.
NOTE: Use only bronze or stainless steel pumps. Do not use pumps
of iron construction as they will oxidize and clog the inlet filter on
the appliance.
Recommendations for domestic hot water recirculation
An Aquastat, with a 5° F differential to control the pump, is
recommended.
The usage of a timer is recommended to limit the energy
consumption. The timer should also limit recirculation pump
operation to the time of day when occupants are home and likely
to use hot water.
Water heater set point must be minimum of 14° F above the
Aquastat setpoint.
Example: Tankless water heater setpoint = 122°F
Aquastat setpoint = 108°F
Keep hot water piping insulated to limit heat loss.
Set temperature on the C 1210 ESC must not exceed 140°F.
5.3 Tank loading
Pressure drop vs. flow
# of
units
Pressure drop vs. flow
Models: C1050ES,
C1210ES, C1210ESC
Pressure drop vs. flow
Model: 940ES/ESO
1 4gpm @ 40 feet of head 4gpm @ 32 feet of head
2 8gpm @ 40 feet of head 8gpm @ 32 feet of head
3 12gpm @ 40 feet of head 12gpm @ 32 feet of head
4 16gpm @ 40 feet of head 16gpm @ 32 feet of head
These guidelines should be followed to maximize system output:
•Ensure flow through each water heater is between 3.5-5.0 gpm
•Isolation valves or boiler drains should installed to facilitate
descaling in applications with hard water.
•Whenever possible, plumb the system or configure the tank to
draw cold supply water into the water heater during hot water
use.
We recommend Grundfos UP26-99, Taco 009 or equivalent potable
water circulators for single unit tank loading installations.

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6 Water Heater Sizing & Specifications
This section describes the water heaters available from Bosch
Thermotechnology Corporation and provides a general overview to
the specifications of that particular model. More detailed
information is contained in the installation manuals. Download
these manuals at www.BoschPro.com.
6.1 Sizing tankless water heaters
Definitions
Major applications (2 GPM or more): Washing machine, bath tub,
shower nozzle
Minor applications(2 GPM or less): Low flow shower head, bath-
room sink, kitchen sink
Rule of thumb sizing
The tables below provide a general rule of thumb when sizing for
most residential applications. For commercial applications or for a
more detailed sizing method, use the Sizing by Chart instructions
below in conjunction with the charts on the next page.
Rule of Thumb Sizing
Model Number Number of Major
Applications
Number of Minor
Applications
C 1210 ES/ESC 3 1
C 1050 ES 2 1
940 ES/ESO 2 0
830 ES 1 2
660EF/EFO 1 1
520 HN/PN 1 0
330 PN 0 1
Sizing by Chart
Measure the flow rates at each fixture that will be used
simultaneously and add them together. If only one application will
be used at a time measure each fixture and use the maximum flow
rate observed
.
Using a known volume container, record several fill times. Per-
form the calculation below to determine the flow rate (a one
gallon fill time of 30 seconds is 2.0 gallons per minute (GPM):
Flow rate (GPM) = Volume (gallons)
Fill time (sec)
sec
min
60
x
Using a thermometer, measure the incoming water temperature.
For reference, see average ground water temperature map. Sub-
tract this temperature from the desired hot water temperature to
get the degree rise. If the desired hot water temperature is 120F
and incoming temperature is 55F, the desired degree rise is 65F.
Figure 1 Average ground water temperatures
EXAMPLE:
• Required flow rate of 2.0 GPM at a 65˚F rise.
• Refer to the graphs on the following page.
• Since the demand is above the 330 PN capacity, this application
would require a 520 HN/PN gas tankless water heater.
•

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0
1
2
3
4
5
6
7
8
520 PN/HN
330
P
N
10 20 30 40 50 60 70 80 90
Degree rise (°F)
GPM
Gas Appl
i
ance S
i
z
i
n
g
Char
t
940 ES
/
ESO
C 1050 E
S
9
10
C 1210 ES
/
ES
C
11
830
E
S
660 EF
/
EFO
12
• Flows above 10 GPM assume installation of a mixing valve to
help mitigate pressure drop in the water heater and plumbing
system