A.O. Smith TWI 45-190, TWI 35-130 Unvented installation, Vented installation, 3 T&P valve

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Operation of the device

2.5Safety of the installation Apart from the standard security of the device, the installation shall further be protected using an expansion vessel, an expansion valve, a pressure reducing valve, a non-return valve and a T&P valve.

The use of an expansion vessel, expansion valve and/or pressure reducing valve is dependent on the type of installation: unvented or vented.

2.5.1Unvented installation

With an unvented installation an expansion valve and an expansion vessel avoid a too high pressure in the tank. This prevents damage to the tank.

A non-return valve avoids a too high pressure on the water piping. This valve also avoids water from the tank flowing into the water piping. The pressure reducing valve protects the installation against a too high water piping pressure (> 8 bars). The parts are mounted into the cold water system (3.6.1 “Cold water side”).

2.5.2Vented installation

With a vented installation the open water tank absorbs the overpressure. The height of the water tank determines the maximum operating pressure in the tank. The maximum operating pressure is 8 bars. The installation shall also be equipped with an expansion valve of the hot water piping that flows out into the water tank. In the ideal situation this should flow out in a separate discharge channel, otherwise in the open water tank. The device shall also have a stop valve on the water side (3.6.2 “Hot water side”).

2.5.3T&P valve

A T&P valve is only obligatory with unvented installations. However, A.O. Smith recommends using a T&P valve with vented installations as well. A T&P valve (Temperature & Pressure valve) monitors the pressure in the tank and the water temperature at the upper part of the tank. The valve will open when the pressure in the tank becomes too high (> 10 bars) or when the water temperature gets too high (> 97°C). The hot water can now flow out of the tank. As the device is under water piping pressure, cold water will automatically flow into the tank. The valve remains open until the unsafe situation has been removed. The device typically has a connecting point for a T&P valve (3.6.2 “Hot water side”).

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Instruction manual TWI 35-130 G/TWI 45-190 G

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Contents 35-130 45-190 Your installer Page Page Copyright 2007 A.O. Smith Water Products Company Page Installation ErrorsMaintenance Operation of the deviceTable of content Warranty certificateIntroduction What to do when you smell gas RegulationsAbout the device Introduction Target groupsInstallation Chapter Target groups DescriptionWarranty certificate This chapter contains the terms of warrantyOperation of the device Introduction This chapter will cover in the given orderHeating cycle Operation of the deviceSecurity of the device Introduction Security of the water temperature Air pressure switchGas control 4 FanVented installation Unvented installation3 T&P valve Installation PackagingInstallation Working area Dimensions of the device Dimension Description TWIDimension Description TWI Description Unit TWIVented Cold water side Hot water sideCirculation piping Condensation drainageAir supply and flue gas discharge Introduction Requirements for flue gas discharge materialDevice types Device types Description Concentric connectionsDevice Diameter Maximum length Maximum num Ber of 90 bends Practical example of concentric flue gas discharge ExampleSpecifications Subject DescriptionParallel connections Device Diameter Maximum running lengthBend Practical example of parallel flue gas discharge ExampleDevice with parallel flue gas discharge material Electrical connection PreparationConnector block Check and adjust the CO2-value Connect the mains voltage Isolating transformerChecking procedure Gas controlAdjust the CO2-value Conversion to another gas category Conversion to another gas category Fill UnventedFill the device Fill unvented installations Fill vented installationsDrain Drain unvented InstallationsDrain vented Opening the gas valve 3.5 Connections diagram Start upStart up Shut down Introduction You canFor a short time Electrically isolateShut down Introduction Distinction is made between General errors ErrorsErrors visible on the control Water leakage Symptom Cause Solution Remark Gas smellExplosive ignition Symptom Cause Solution Remark Insufficient or no Hot waterTroubleshooting table for errors visible on the control Light pulses Cause Solution RemarkLight pulses Cause Solution Remark SL3 See 12.2 Electrical circuit diagramTWI Maintenance Introduction Prepare maintenanceMaintenance Warranty certificate 11.1 Warranty general11.2 Warranty tank 11.3 ConditionsWarranty certificate 11.6 Claims11.7 Obligations SmithAnnex Electrical circuit diagram AnnexWiring Annex Index ConnectUser Warranty IndexPage 0308 489 R1.0

TWI 35-130, TWI 45-190 specifications

A.O. Smith TWI 35-130 and TWI 45-190 are high-efficiency water heaters designed to meet the diverse needs of residential and commercial applications. These units are part of A.O. Smith’s extensive product line, known for reliability, durability, and energy efficiency.

The TWI 35-130 model is a 35-gallon tank water heater, offering a first-hour delivery of 130 gallons. This capacity makes it suitable for households with moderate hot water demands. It features a compact design, allowing for easy installation in tighter spaces, which is ideal for urban settings. The unit operates on natural gas, promoting energy efficiency while reducing operational costs.

One of its main attributes is the advanced insulation technology that minimizes heat loss, thus enhancing overall energy efficiency. The TWI 35-130 is equipped with a state-of-the-art burner system that optimizes combustion for higher efficiency, translating to lower energy bills. Furthermore, it utilizes a dip tube that helps in delivering hot water promptly, ensuring that the demand for hot water is met swiftly.

On the other hand, the TWI 45-190 model caters to larger households or commercial settings with a 45-gallon capacity and a first-hour delivery of 190 gallons. This model also uses natural gas, but with a higher BTU rating, allowing for faster recovery rates, which is crucial during peak usage times.

Both models are designed with user-friendliness in mind, featuring intuitive controls that facilitate easy temperature adjustments and monitoring. Additionally, they incorporate safety features such as a temperature and pressure relief valve to prevent overheating and excessive pressure build-up, ensuring peace of mind for users.

Their innovative design also emphasizes longevity, with high-grade materials and protective coatings that resist corrosion and extend the lifespan of the tank. The TWI series stands out in the market not only for its performance and efficiency but also for its commitment to sustainability.

In summary, A.O. Smith's TWI 35-130 and TWI 45-190 water heaters bring together cutting-edge technology, efficiency, and reliability, making them excellent choices for both residential and commercial applications. With features designed to promote energy savings and user convenience, these models are poised to meet the hot water demands of modern life while adhering to high standards of safety and durability.
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