S U F S E R V I C E H A N D B O O K

T R O U B L E S H O O T I N G

PRESSURE SWITCH PERFORMANCE

STEP 9A

TAKE AIR AND GAS PRESSURE READINGS.

Blower prover and blocked outlet pressure

Blower inlet pressure

STEP 9A: CHECK PRESSURE AT SENSING PORTS ON BURNER, BLOWER INLET AND GAS VALVE.

Condition:

•All wires are reconnected to all pressure switches.

•On/Off switch is on.

•Call for heat is activated.

•Blower is running during trial for ignition.

Remove the air pressure sensing tubes from the sensing ports on the blower inlet and the burner. Using a digital manometer take a pressure reading with the blower running during a call for heat at both of these sensing ports. Take a supply gas pressure reading on the inlet side of the gas valve as outlined in Step 13.

Record all 3 pressure readings and have them on hand. Continue to Step 9B.

AMBIENT ROOM AIR PRESSURE

N O T E : One side of the internal diaphragms on these pressure switches are vented to the room atmosphere. Due to this construction a negative or positive room air pressure can cause erratic switch operation and the water heater to shut down. If you suspect a pressure imbalance between the equipment room and the outdoor atmosphere, “zero” or calibrate your digital manometer to the equipment room ambient air pressure. With the manometer still on and calibrated to the equipment room air pressure take the manometer outdoors. If the pressure reading changes significantly you may have a pressure imbalance between the equipment room and the outdoor atmosphere. This pressure imbalance may need to be corrected before the water heater will operate properly.

Insure the combustion/make-up air openings into the equipment room are properly sized. Check for leaks in ductwork on any nearby air handling equipment. If there is a kitchen vent hood installed in the building, insure it is properly balanced. Missing or worn fan belts on make up air fans to vent hoods can cause negative air pressure throughout the building.

Direct vent installations DO NOT eliminate this potential problem.

Technical Training Department

26

State Water Heaters

STC-077

Ashland City, Tennessee © 2004

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State Industries STC-077 Pressure Switch Performance, Take AIR and GAS Pressure Readings, Ambient Room AIR Pressure
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STC-077 specifications

The State Industries STC-077 is a notable addition to the realm of high-efficiency water heaters, exemplifying advanced engineering and innovative design. The STC-077 is particularly recognized for its exceptional performance and energy-saving capabilities, making it an ideal solution for both residential and commercial applications.

One of the standout features of the STC-077 is its impressive energy efficiency rating. Utilizing state-of-the-art technology, this water heater operates with a high energy factor (EF) that significantly reduces operating costs compared to traditional water heating systems. This is especially beneficial in today's climate of rising energy costs and increased environmental awareness.

The STC-077 employs a robust stainless-steel tank construction that not only provides durability but also mitigates the risk of corrosion, ensuring longevity and reliability. This innovative design approach helps extend the product's lifespan while maintaining consistent performance throughout its use. Coupled with superior insulation, users can expect minimal heat loss and enhanced energy efficiency, making it a sustainable choice for consumers.

The unit is equipped with advanced controls that provide precise temperature regulation. This feature improves user experience and safety, allowing for customization to meet individual needs. Additionally, the STC-077’s intuitive digital display makes monitoring and adjusting settings straightforward, providing convenience and ease of use.

In terms of capacity, the STC-077 offers versatility with options suitable for various household sizes and demands. Whether for a small apartment or a busy commercial establishment, its modular design allows for seamless integration into existing systems while providing adequate hot water supply.

Furthermore, the STC-077 incorporates innovative technologies aimed at reducing maintenance needs. With easy access for servicing and built-in diagnostics, users can monitor performance proactively, ensuring the unit operates at optimal efficiency.

Overall, the State Industries STC-077 shines as a forward-thinking water heater. Its combination of high energy efficiency, durable construction, advanced technology, and user-friendly features make it a comprehensive solution for those seeking reliable hot water with minimal environmental impact. Whether for homeowners looking to lower energy bills or businesses seeking dependable performance, the STC-077 stands out as a premier choice in water heating solutions.
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