Lochinvar 497 - 2067 Electrical connections continued, Temperature adjustment, B, Notice

Installation & Service Manual

5 Electrical connections (continued)

Temperature adjustment

Note: The temperature controller is preset at the factory with test settings. You may need to adjust the settings to meet your specific needs.

WARNING Return water temperatures must not be less than 140°F. If lower return water temperatures

are required, follow the instructions for Low Temperature Return Water Systems on page 30.

Locating the temperature control

The temperature control is located behind the panel on the left front of the unit (see FIG. 5-6). Follow the steps below to access the temperature control.

1.Loosen the knurled knob at the bottom of the control panel cover.

2.Pull the bottom of the panel out and down to remove.

Figure 5-7_Temperature control setting knobs

OJ1

OJ2

SETPOINT		HIGH-FIRE
		OFFSET
	DIFFERENTIAL

OJ1

OJ2

Temperature control settings

There are three setting knobs on the temperature control unless your unit is specified as a boiler only with an outdoor air reset option. If your unit is a boiler only with an outdoor air reset option, there are additional controls for this option. They are explained under Outdoor Air Reset Option, page 40.

The three setting knobs on the temperature control are for Set Point, Differential, and High-Fire Offset (see FIG. 5-7).

Maximum set point

The maximum set point for the control is factory set. Boilers are set to 230°F max., water heaters are set to 190°F max., and specialty state and local codes to 200°F.

These maximum set points are established by not cutting/ cutting the OJ1 and OJ2 jumpers located on the right side of the temperature controller (see FIG. 5-7). The maximum set point is determined as shown in Table 5B.

Figure 5-6_Locating temperature control

TEMPERATURE

CONTROL

TABLE 5B

Maximum Setpoint Determination

OJ1	OJ2	Max.
		Setpoint
Connected	Connected	230°
Cut	Connected	190°
Connected	Cut	200°
Cut	Cut	160°

NOTICE	Anytime that OJ1 is the only jumper cut, a
	new overlay is required under the Set Point
	knob on the temperature controller because
	the scale has changed to a maximum of
	190°F.

Anytime the OJ2 jumper is cut (with or without OJ1), a new overlay is required under the Set Point knob on the temperature controller because the scale has changed to a maximum of 200°F.

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