CONTROLS AND SWITCHES

This model is provided with three pressure switches. These switches are essential to the safe and proper operation of the unit. All switches are wired in series. The controller is set up to shut the unit down whenever there is a failure of any of the switches. It is important to understand the purpose of each switch.

Figure 33.

BLOWER PROVER SWITCH

(SEE FIGURE 33)

The Blower Prover Switch is provided on the heater to verify that the fan is operating. It is a positive pressure switch whose electrical contacts are normally open. When the fan increases the pressure in the burner, the pressure switch will allow the electrical contacts to close. The pressure switch is connected to the burner tap by a piece of tygon tubing. This tubing must be connected in order for the switch to change the electrical contacts. The controller requires that the electrical contacts on this air flow switch be open before it will allow the blower to come on.

BLOCKED EXHAUST SWITCH

(SEE FIGURE 33)

The Blocked Exhaust Switch is set up to shut the unit off when a build-up of positive pressure in the exhaust vent pipe occurs. This switch is a positive pressure switch that requires an increase in

pressure to change the electrical contacts from normally closed to open. When this switch prevents the unit from igniting, most likely the exhaust is blocked by some means. Check to see if the condensate is allowed to flow freely from the exhaust elbow and for obstructions in the exhaust venting and exhaust vent terminal. Also verify that the vent length does not exceed the maximum allowed as shown in the Vent Section of this manual.

BLOCKED INTAKE SWITCH

(SEE FIGURE 33)

The Blocked Intake Switch is set up to shut the unit off when a build-up of negative pressure in the intake air pipe occurs. This switch is a negative pressure switch that requires an increase in negative pressure to change the electrical contacts from normally closed to open. The switch is connected to the pressure tap on the PVC pipe connected to the inlet of the blower. When this switch prevents the unit from igniting, most likely the intake is blocked. Verify that the screen on the intake air connection (conventional vent), the intake air pipe and termination (direct vent installations) are free of obstructions that may prevent air from entering the unit. Insure the screen on intake air connection has been removed on direct vent installations, see Figure 15. Also verify the intake air pipe length does not exceed the maximum allowed as shown in the Vent Section of this manual.

ON/OFF SWITCH

The ON/OFF Switch is a single-pole, single-throw rocker switch. This switch provides 120V from the line source to the heater.

CAUTION

THE WATER HEATER IS POLARITY SENSITIVE. BEFORE APPLYING ELECTRICITY TO THIS HEATER BE CERTAIN THAT SUPPLY NEUTRAL WIRE TO GROUND CHECK INDICATES ZERO VOLTAGE.

HOT SURFACE IGNITER

The Hot Surface Igniter is a device that ignites the main burner by high temperature (>1800°F or >982°C). When 120VAC is applied to the igniter, sufficient heat is generated to ignite the main burner.

33

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Image 33
A.O. Smith 100 Power Vent DV Series 120 Blower Prover Switch, Blocked Exhaust Switch, Blocked Intake Switch, ON/OFF Switch
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100 Power Vent DV Series 120, 317443-000 specifications

The A.O. Smith 317443-000,100 Power Vent DV Series 120 is an advanced water heating solution designed to enhance efficiency and performance for residential applications. As part of A.O. Smith's renowned lineup, this model embodies the company's commitment to innovation and energy conservation.

One of the main features of the DV Series 120 is its power venting capability. This technology allows for flexible installation options, as it can vent vertically or horizontally, accommodating various home configurations. It utilizes a fan-assisted venting system, which efficiently expels exhaust gases, ensuring safe operation even in tight spaces.

The unit's energy efficiency is another standout characteristic. Equipped with a high-efficiency gas burner, the DV Series 120 optimizes fuel consumption, resulting in lower utility bills while providing reliable hot water when needed. Its impressive Energy Factor (EF) ratings make it an environmentally friendly choice, aligning with modern standards for green building practices.

Durability is also a significant focus of the A.O. Smith 317443-000,100 Power Vent model. Constructed with a glass-lined tank and a robust anode rod, this water heater is designed to resist corrosion and extend its lifespan. This construction enhances performance reliability while minimizing maintenance needs, making it a smart investment for homeowners.

Smart technologies are integrated into the DV Series 120, featuring an intelligent control system that provides various operational insights. The built-in diagnostic features allow homeowners to monitor performance and identify potential issues early, reducing the likelihood of unexpected failures. This control system can also enable more precise temperature management, enhancing both comfort and efficiency.

Safety is paramount in the design of the A.O. Smith 317443-000,100. The unit comes equipped with safety features such as a built-in flame rollout sensor and an automatic shut-off system to protect against potential hazards. These features ensure peace of mind for users, allowing them to confidently rely on their hot water supply.

In summary, the A.O. Smith 317443-000,100 Power Vent DV Series 120 stands out as a high-efficiency water heating solution, combining innovative venting technologies, durability, smart features, and safety mechanisms. This model is an ideal choice for homeowners seeking a reliable and efficient hot water system that meets modern energy standards.
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