INSTALLATION (con’t)

SYSTEM WIRING

NOTE

REFER TO AND FOLLOW THE APPLIANCE MANUFACTURER’S WIRING DIAGRAM. REFER TO FIG. 4 FOR TERMINAL IDENTIFICATION.

All wiring should be installed in accordance with local and national electrical codes and ordinances.

Check that the electrical power supply used agrees with the voltage and frequency shown on the gas control.

Main Valve

1

2

Redundant

Valve Coil

(Pilot Valve)

3

4

Figure 4. Typical gas valve wiring

ADJUSTMENT

PILOT FLAME ADJUSTMENT

This control was factory preset and will not normally require additional adjustment of pilot flame.

If the pilot flame is low and does not engulf the bulb of the mercury flame sensor, the system will not energize the main valve.

If pilot gas pressure is too high, gas will sputter past the ignition electrode, and may not ignite. High pilot gas pressure may also cause the flame to lift off the burner, causing the flame sensor bulb to sense “low” heat.

To adjust the pilot flame, remove the pilot adjust cover screw and gasket (see fig. 6) to expose adjusting screw. To REDUCE pilot flame, turn the pilot adjust screw clockwise. To INCREASE pilot flame, turn the pilot adjust screw counterclockwise. Replace and tighten cover screw and gasket.

Pilot Adjust

Cover Screw

Gasket

Pilot

Adjust

Screw

PRESSURE REGULATOR

ADJUSTMENT

The pressure regulator has been factory adjusted for 3.5” W.C. (Natural Gas, full flow) or 11.0” W.C. (LP Gas, full flow). Although additional adjustments will not nor- mally be necessary, the regulator may be adjusted if required. Do not force the adjusting screw beyond the limits that it can easily be adjusted.

1.Attach a manometer to the outlet pressure tap of the valve.

2.Energize valve to ignite main burner.

3.Remove “Reg. Adj.” cover screw (see fig. 6).

4.To DECREASE outlet pressure, turn the adjusting screw (beneath the cover screw) counterclockwise. To INCREASE outlet pressure, turn the adjusting screw clockwise.

5.Replace the cover screw. Cycle the valve two or three times to verify regulator setting.

NATURAL-LP

GAS SELECTOR

REGULATOR￿

COVER SCREW

ON

OFF

PILOT ADJUST

COVER SCREW

Figure 5. Pilot flame adjustment

Figure 6. Gas valve top

4

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White Rodgers 36C74 System Wiring, Adjustment Pilot Flame Adjustment, Pressure Regulator Adjustment
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36C74 specifications

The White Rodgers 36C74 is a robust and versatile thermostat designed primarily for managing heating and cooling systems in residential and commercial applications. Known for its reliability and ease of use, the 36C74 is widely appreciated by both homeowners and HVAC professionals alike.

One of its standout features is its compatibility with a diverse range of heating and cooling systems, including gas, oil, and electric furnaces, as well as heat pumps and central air conditioning systems. This flexibility allows users to integrate the thermostat seamlessly into their existing setups without any additional hassle.

The 36C74 boasts a user-friendly interface that includes a large, clear display, making it easy to read and operate. The intuitive controls enable users to set the desired temperature effortlessly. This management of indoor climate is made even more convenient with the programmable option, allowing users to schedule temperatures based on their daily routines.

In terms of technology, the White Rodgers 36C74 is equipped with advanced temperature sensing capabilities that ensure precision in maintaining the desired indoor climate. Its adaptive recovery technology allows the thermostat to learn how long it takes to reach a set temperature, adjusting its heating or cooling cycles accordingly. This feature not only enhances comfort but also contributes to energy savings by preventing unnecessary operation of HVAC systems.

Another notable characteristic of the thermostat is its 7-day programmability. Users can easily create customized schedules for each day of the week, providing optimal comfort when supplemented with cost savings on energy bills. Additionally, the thermostat includes a vacation mode, which temporarily adjusts the home’s temperature settings during extended periods away, further optimizing energy efficiency.

The 36C74 also supports easy installation and setup, with labeled wiring terminals to help eliminate confusion during the installation process. Moreover, the thermostat is designed to work with a wide variety of power sources, adding to its versatility.

With a combination of advanced technology, energy efficiency, and user-friendly design, the White Rodgers 36C74 thermostat stands out as a reliable choice for effective climate control, making it a popular option for enhancing home comfort. Whether you are looking to optimize your heating or cooling systems, the 36C74 provides a perfect blend of capabilities to meet your needs.
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