MODEL 250SX NG and 250SX LP Temperature Modulated with Electronic Ignition Suitable for heating potable water only Not approved for space heating purposes (Intended for variable flow applications with multiple tapping points) 250 SX NG 250 SX LP 6 720 607 057 (04.05) JS Warning: If the information in this manual is not followed exactly, a fire or explosion may result causing property damage, personal injury or death.
Index Index 1 Warning 2 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.9.1 2.10 2.11 2.12 2.13 2.14 2.15 2.16 2.
Warning Warning: Field wiring connections and electrical grounding must comply with local codes, or in the absence of local codes, with the latest edition of the National Electric Code, ANSI/NFPA 70, or in Canada, all electrical wiring must comply with the local codes and the Canadian Electrical Code, CSA C22.1 Part 1. Warning: Shock hazard line voltage is present. Before servicing the water heater, turn off the electrical power to the water heater at the main disconnect or circuit breaker.
Appliance details 2 Appliance details 2.1 Features Maximum input 175,000 Btu/h (51.2 kW) Parts • Touch Pad interface control Efficiency in % • High power pre-mix compact burner with low Nox emissions Recovery efficiency 86.5% • Modulating Gas Valve with constant gas:air ratio control Min. Output 31,131 Btu/h (9.1 kW) • Modulating water valve for improved comfort and temperature control.
Appliance details • Minimum recommended water pressure: 30 PSI (2.07 bar) UNPACKING THE 250 SX HEATER • Connections: – Bottom of heater The box includes: Combustion • Bracket for wall hanging the heater • NOx ≤ 55 ppm • Exhaust vent adaptor (with 4 screws and gasket provided) • CO ≤ 250 ppm • CO2 level set from factory, see chapter 9.1. Dimensions • Depth (in): 8 ½” (220 mm) • Width (in): 15 ¾” (400 mm) • Height (in): 23 ½” (600 mm) • Weight: 47 pounds (21 kg). Gas types Natural Gas. LP Gas.
Appliance details 2.3 Dimensions and Minimum installation clearances Fig. 5 Dimensions 1 2 3 4 5 6 Cover On/Off switch Reset button LCD display Program button Temperature buttons Fig.
Appliance details 2.4 General rules to follow for safe operation B 1. You should follow these instructions when you install your heater. In the United States: The 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: The Installation should conform with CGA B149.(1,2) INSTALLATION CODES and /or local installation codes. B 2. Carefully plan where you install the heater.
Appliance details 2.6 Clearances The 250 SX is design certified for installation on a combustible wall (see 2.7 Mounting installation) provided the floor covering below the heater is noncombustible. For installations in an alcove or closet, maintain the minimum clearances to combustible and non-combustible materials listed below. See also Fig. 6. A. Top 12 inches (306 mm) B. Front 4 inches (102 mm) C. Back 0 inches D. Sides 4 inches (102 mm) E.
Appliance details – b) In unconfined spaces in buildings of conventional frame, masonry, or metal construction, infiltration air is normally adequate to provide air for combustion. Establish vent clearances that comply with the vent manufacturer's specifications. In all cases follow local codes. See table 2. • Appliances located in confined spaces: The confined space must be provided with two permanent openings, one commencing within 12 inches (304.
Appliance details The maximum flue gas exhaust temperature on the 250 SX is 437°F (225°C) Venting Options Exhaust vent diameter and material * Exhaust vent maximum length * Exhaust vent minimum length Combustion air pipe diameter and material Combustion air pipe maximum length Vent pipe clearances within an unenclosed space Vent pipe clearances within an enclosed space Room sealed (twin pipe) 3 inch stainless steel (AL29-4C) sealed vent pipe 26 feet (8 m) with one elbow.
Appliance details The appliance should be located as close to the point of termination as possible. The maximum vent length is 26 feet (8 m) with one 90 degree elbow. Subtract 2½ feet from the total vent length for each additional 90° elbow used (a maximum of three 90° elbows are permitted in the total vent length), or subtract 1 ¼ feet for every 45° elbow used. Horizontal sections of vent must pitch ¼" for every foot of horizontal length and be supported at 4 foot intervals with overhead hangers.
Appliance details Room sealed installation (TWIN PIPE SYSTEM) Open combustion installation (SINGLE PIPE SYSTEM) Fig. 12 Combustion air pipe: ≤ 26 ft (8 m) Exhaust vent pipe: ≤ 26 ft (8 m) If the total horizontal exhaust vent length in a side wall installation is greater than or equal to 5 feet (1.5m), a condensate drain tube must be attached to the exhaust collar. See page 14. Fig.
Appliance details Recommended exhaust vent terminator position Fig. 16 Ref.
Appliance details Supporting the exhaust vent system and the use of an external condensate trap External condensate traps If the total horizontal exhaust vent length in a side wall installation is greater than or equal to 5 feet (1.5m), a condensate drain tube must be attached to the exhaust collar. B A condensate trap must be used in any sidewall exhaust vent installations when the total vent length is ≥ 5 ft (1.5 m) OR the vent pipe passes through an unheated space (below 60F).
Appliance details A condensate drain tube must be attached to the exhaust collar of the heater for any vertically exhausted vents, see page 14. 2.10 Gas piping & connections Before connecting the gas supply, check the rating plate on the right side of the heater to be sure that the heater is rated for the same gas to which it will be connected. In the United States: The installation must conform with local codes or, in the absence of local codes, the National Fuel Gas Code ANSI Z223.1/NFPA 54.
Appliance details FOR NATURAL GAS Maximum Capacity of pipe in Cubic Feet of Gas per Hour for Gas Pressure of 0.5 Psig or less and a Pressure drop of 0.3 in Water Column (0.75mbar).(Based on a 0.60 Specific Gravity Gas) Btu numbers given in thousands. Follow boxed numbers for piping just one 250 SX (example: ¾” B.I. Natural Gas pipe for 20 ft (6.1m). will handle 190,000 btu’s (55.7 kWh). For multiple appliances combine the total btu input load and then refer to applicable chart below.
Appliance details 2.11 Gas line sizing B It is strongly recommended that the Natural Gas pipe be Black Iron pipe the entire distance from the outside meter to the inlet of the gas connection. ¾” Black Iron pipe up to 20 feet (6.1m) and 1” Black Iron pipe up to 70 feet (21.34m) distances. Flex line is NOT recommended, but if used, then oversize the diameter of the flex pipe, keep the length to a minimum and try to keep the flex line as straight as possible.
Appliance details 2.13 Water connections Connecting the pressure relief valve (PRV) When facing the heater, the ¾” cold water inlet is on the bottom right and the hot water outlet is on the bottom left. Install the heater centrally in the building if possible and make hot water piping runs as short as possible. A listed pressure relief valve supplied with the heater must be installed at the time of installation. No valve is to be placed between the PRV and the heater.
Appliance details 2.14 Electrical connections Warning: For safety reasons, disconnect the power supply to the heater before any service or testing is performed. Warning: This heater must be electrically grounded in accordance with the most recent edition of the National Electrical Code. NFPA 70. In Canada, all electrical wiring to the heater should be in accordance with local codes and the Canadian Electrical Code, CSA C22.1 Part 1.
Appliance details i NOTE: on a first time initial installation or after gas line work has been done, existence of air in the gas line will cause ignition delay when the hot water is turned on. This will result in an error (EA) on the units display screen. This is normal. When this occurs, leave the hot water running and wait 3-5 seconds, then reset the unit (Fig. 26, pos. 2). Wait for (EA) to disappear.
Operation instructions 3 Operation instructions Fig. 26 1 2 3 4 5 6 On/Off switch Reset button Program Key Increasing temperature selector Decreasing temperature selector LCD display 3.1 B Press buttons and requested temperature. in order to reach Power On B To start the appliance switch the button to position (I). LCD display the default temperature - temperature factory setting 122°F (50°C). Fig.
Operation instructions Setting the water temperature The desired temperature of the hot water can be adjusted on the front control panel of the heater. The 250 SX has an electronically controlled gas valve that modulates the burner input in response to both varying hot water flow rates and/or changes in any incoming and outgoing water temperatures. Hot Water Flow and Temperature with Various Inlet Temperature (gpm/Fahrenheit) 7.00 Hot Water Flow (GPM) 6.00 5.00 4.00 3.00 2.00 1.00 0.
Operation instructions 3.3 Use of remote control accessory Fig. 33 Reset button If the problem persists, contact your installer. Fig. 30 Remote control 3.6 The wireless remote control accessory and the temperature selector buttons on the front of the water heater operate identically. Contact your distributor or CEC to order if the remote control accessory is preferred. Modification of the water heaters interior control unit (Fig.
Maintenance and service 4 Maintenance and service Warning: Always turn off the electrical power supply, turn off the manual gas valve and turn off the manual water control valves whenever servicing. The unit should be checked once a year by a gas technician. If repairs are needed, the repairs should be done by a gas technician To remove front cover B Remove plastic decals on front panel (Page 5, Fig. 4). B Loosen the two Philips head screws located behind decals.
Troubleshooting Test by following 4th bullet under BURNERS DO NOT IGNITE WHEN HOT WATER IS TURNED ON. LOW WATER FLOW/PRESSURE • Too many hot water applications are being used simultaneously or too much flow is being demanded The 250 SX will effectively support two 2.0-2.5 gpm shower heads simultaneously or multiple sink applications. Greater draws will result in increased pressure drop and reduced flow at taps. See flow/ temperature chart on page 22.
Troubleshooting Display Cause Solution E9 Temperature limiter opened circuit (overheat). Trips at 220F (104C). Check connections.* Check heat exchanger condition.* EA No ionization during safety time (safety time out). EC The ionization signal momentarily disappeared more then 3 times in less then 30 seconds. Check gas pressure.* Check that gas is not diluted with air, as a result from recent gas pipeline rework.*.
Electrical diagram 6 Electrical diagram Fig.
250 SX Functional scheme 7 250 SX Functional scheme Fig.
Interior components diagram and parts list 8 Interior components diagram and parts list 8.1 Interior components Fig. 38 Components 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Cover On/Off switch Reset button LCD display Program button Temperature switches Flue gas collector Mixer Heat exchanger Observation window Inlet air duct Control unit Exhaust fan Water valve Gas valve Fig.
Interior components diagram and parts list 8.2 Components diagram Fig.
Interior components diagram and parts list 8.
Special adjustment for measuring and adjusting CO2 levels 9 Special adjustment for measuring and adjusting CO2 levels The CO2 can only be adjusted by a certified gas technician with a calibrated CO2 analyzer. Caution: Converting the gas type can only be done by a certified gas technician with a calibrated CO2 analyzer. Call CEC for conversion instructions. Caution: Adjustments must only be carried out by authorized service personnel only.
Special adjustment for measuring and adjusting CO2 levels i NOTE: turning screw clockwise decreases CO2 level, turning counterclockwise increases it. Caution: Faulty ignition or noisy operation may occur if CO2 levels are adjusted outside the indicated range. Fig. 43 Adjusting Leave “Program” mode B Turn ON/OFF switch in position OFF and then ON again.
Protecting the environment 10 Protecting the environment Packing The packing box may be fully recycled as confirmed by the recycling symbol . Components Many parts in the heater can be fully recycled in the end of the product life. Contact your city authorities for information about the disposal of recyclable products. Saving water resources: B Make sure you close all the taps after any use. Avoid leaving the taps dripping. Repair any leaking tap.
Twelve Year Limited Warranty 11 Twelve Year Limited Warranty General Service Labor Costs Aquastar water heaters are warranted by the Manufacturer (BOSCH) through Controlled Energy Corp. Controlled Energy Corp. (CEC) will furnish a replacement heat exchanger and will furnish a replacement of any other part which fails in normal use and service within the applicable periods specified below, in accordance with the terms of this warranty.
Replacement Parts available from North American Distributor CONTROLLED ENERGY CORP. 340 Mad River Park Waitsfield, Vermont 05673 VULCANO Termodomésticos S.A. Phone 800-642-3111 Estrada de Cacia 3801 - 856 Aveiro - PORTUGAL Fax (802) 496-6924 www.controlledenergy.com/tech techsupport@controlledenergy.