Bosch C 1050 Manual

C 1050 ES
INDOOR MODEL 
Temperature Modulated with Electronic Ignition 
Suitable for heating potable water and space heating
(Intended for variable flow applications)
C 1050 ES - Natural Gas 
C 1050 ES - Liquefied Petroleum (LP) Gas
6 720 644 894 (2010/09) US
Warning:  If  the  information  in  this  manual  is  not
followed  exactly,  a  fire  or  explosion  may  result 
causing property damage, personal injury or death.
Do  not  store  or  use  gasoline  or  other  flammable
vapors and liquids in the...

6 720 644 8942
Index
Index
1 Warning  3
2 Appliance details  5 
2.1 Features  5
2.2 Specifications (Technical data)  5
2.3 Unpacking the heater  6
2.4 General rules to follow for safe operation  8
2.5 Dimensions and minimum 
installation clearances  9
3 Installation instructions  10 
3.1 Specialized tools  10
3.2 Introduction  10
3.3 Venting   10
3.4 Combustion air requirements  24
3.5 Proper location for installing your heater  25
3.6 Heater placement and clearances  25
3.7 Mounting installation  25
3.8...

6 720 644 894
Warning3
1 Warning
For your safety 
Do  not  store  or  use  gasoline  or  other  flammable, 
combustible  or  corrosive  vapors  and  liquids  in  the
vicinity of this or any other appliance.
Warning:  Carefully  plan  where  you
install  the  heater.  Correct  combustion 
air  supply  and  flue  pipe  installation  are
very important. If a gas appliance is not
installed  correctly,  fatal  accidents  can
result  such  as  carbon  monoxide
poisoning or fire.
Warning:  Exhaust gas must be...

6 720 644 8944
Warning
FCC: 
This device complies with Part 15 of the FCC rules. 
Operation is subject to the following two condition s: (1) 
This device may not cause harmful interference, and  (2) 
this device must accept any interference received, 
including interference that may cause undesired ope ra-
tion. 
Fig. 1
Warning:  If  a  relief  valve  discharges
periodically,  this  may  be  due to  thermal 
expansion  in  a  closed  water  supply
system.  Contact  the  water  supplier  or
local...

6 720 644 894
Appliance details5
2 Appliance details
2.1 Features
Parts 
• Key Pad interface control 
• High  power  pre-mix  compact  burner  with  low  NOxemissions
• Modulating  Gas  Valve  with  constant  gas:air  ratio control 
• Modulating  water  valve  for  improved  comfort  and temperature control.
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.
Features 
• Easily...

6 720 644 8946
Appliance details 
Combustion 
• NOx 
 14 Ng/J 
(Nanograms of NOx (calculated as NO
2) per 
Joule of heat output).
• CO   290 ppm (measured)
• CO
2 level set from factory, see chapter 6.5, page 43.
Dimensions 
• Depth (in): 11¼” (286 mm) 
• Width (in): 17 
7/8” (452 mm)
• Height (in): 30½” (775 mm) 
• Weight: 74 pounds (33.5 kg). 
Gas types 
Natural Gas. 
LP Gas. 
Voltage 
120 V AC (60 Hz) nominal 
Amperage 
Idle - 40 mA 
Operation -
   2.5 A
Noise 
45 - 65 db (A) 
Safety devices 
• Flame...

6 720 644 894
Appliance details7
To remove front cover B
Loosen  the  two  Phillips  head  screws  located  on 
bottom rear of cover (see Fig. 3).
Fig. 3 Loosen the two screws B Lift front cover panel upward and remove.
Fig. 4 Remove the front cover 
To remove combustion cover (service only) B Open  the  four  clips  and  remove  the  combustion 
cover (see Fig. 5). Fig. 5 Remove the combustion cover
6720644956-11.1V 

6 720 644 8948
Appliance details
2.4 General rules to follow for safe 
operation
B1.  You  must  follow  these  instructions  when  you
install  your  heater.  In  the  United  States:  The 
installation  must  conform  with  local  codes  or,  in  t he
absence of local codes, the National Fuel Gas Code
ANSI Z223.1/NFPA 54.
In  Canada:  The  Installation  must  conform  with  CSA
B149.(1,2)  INSTALLATION  CODES  and  /or  local
installation codes.
B 2. Carefully plan where you install the heater. Correc...

6 720 644 894
Appliance details9
2.5 Dimensions and minimum installation clearances
Fig. 6 Dimensions
1On/Off button
2 Reset button
3 Program key
4 Power ON or stand-by LED
5 LCD display
6 Up button
7 Down button
Fig. 7 Minimum clearances 
Note:  For  servicing  access,  a  2ft  clearance  is 
recommended to the front cover.
6720608000-03.2AL
6
4
Model C 1050 ES
TOP (A) 12”
FRONT (B) 1”
BACK0”
SIDES1”
FLOOR (C)12”
Table 1 Minimum clearances 

6 720 644 89410
Installation instructions
3 Installation instructions
3.1 Specialized tools
The following specialized tools may be required for
 
installation: 
• Manometer 
• Multi-meter 
• Combustion Gas Analyzer.
3.2 Introduction
Please  follow  these  instructions.  Failure  to  follow 
instructions may result in: B Damage or injury.
B Improper operation.
B Loss of warranty.
3.3 Venting 
3.3.1 Vent material 
All combustion air and vent pipe materials and fitt ings 
must comply with the following:...