Lochinvar 1.5, 1.3 SH off-ondifferential SH off/on df, Offset HW setpoint to end HW demand

PC Program Instructions

6Parameters

SH off-on differential (SH off/on df)

The SH Off-on Differential sets how many degrees below the turn-off temperature the outlet temperature has to go before the boiler will turn on. This parameter can be changed by accessing parameter 4AE. The temperature range of this parameter is 0°F to 86°F. The default value is 20°F.

Drop of inlet temp before ending anti-cycling (Drop in inlet)

The control will bypass the anti-cycling time if the inlet water temperature drops too much. The control will use the inlet water temperature when it shuts off as the starting point. If the temperature drops this amount below the starting temperature, the control will abort anti-cycling and allow the boiler to fire. This parameter can be changed by accessing parameter 4AF. The temperature range of this parameter is 0°F to 86°F. The default value is 10°F.

Offset HW setpoint to end HW demand

When heating an indirect hot water tank (heat maker), the tank temperature (or inlet temperature if a tank sensor is not used) must rise above the tank setpoint (parameter 4AS) by this amount before the HW heat demand will end. This parameter can be changed by accessing parameter 4AG. The temperature range of this parameter is 0° to 54°F (30°C). The default setting is 0°.

Outdoor air shutdown temp (Out SD Setp)

When the outdoor air temperature rises above this point, the control will inhibit all SH demands (HW demands will still be active). This parameter can be changed by accessing parameter 4AH. The temperature range of this parameter is 0°F to 120°F (99°C). The default value is 80°F (27°C).

OA shutdown differential (Out SD df)

This is the number of degrees below parameter 4AH the outdoor air temperature must go before the boiler will again respond to an SH demand. This parameter can be changed by accessing parameter 4AI. The temperature range of this parameter is 0°F to 90°F (50°C). The default value is 10°F (5°C).

Shift OA reset curve (Shift Air Reset)

The Shift Heat Curve shifts the actual setpoint above or below the calculated setpoint by the number of degrees in this parameter. This parameter can be changed by accessing parameter 4AJ. The temperature range of this parameter is -27°F (-15°C) to 27°F (15°C). The default value is 0°. This feature will be active if this parameter is set to anything other than 0°.

Night setback temperature (NSB Setp)

Once the internal clock has been set correctly, the night setback feature can be used to program a lower water temperature setpoint for space heating. This parameter can be changed by accessing parameter 4AK. The temperature range for this parameter is 32°F (0°C) to 140°F (60°C). With a setting of 32°F (0°C) the feature is turned off. The default value will be 32°F (0°C).

SH turn-off differential cascade (Casc off df)

The SH turn-off differential cascade sets how many degrees above the SH setpoint the system temperature has to go before the boiler will shut off. This parameter can be changed by accessing parameter 4AL. The temperature range of this parameter is 0°F to 72°F (40°C). The default setting is 10°F (5°C).

SH off-on differential cascade (Casc off/on df)

The SH off-on differential cascade sets how many degrees below the turn-off temperature the system temperature has to go before the boiler will turn back on. This parameter can be changed by accessing parameter 4AM. The temperature range of this parameter is 0°F to 72°F (40°C). The default setting is 20°F (10°C).

SH anti-cycling time (Anti-C t)

Once a SH demand has been satisfied, a set amount of time must elapse before the control will respond to a new SH demand. This helps prevent short cycling of the boiler. The control will inhibit the new heat demand and “Anti-cycling” will be shown on the display, until either this time has elapsed or the water temperature drops below parameter 4AF. This parameter can be changed by accessing parameter 4AO. The time range for this parameter is 0 minutes to 40 minutes. The default value is 1 minute.

Max service time (Max Serv t)

The service mode allows the installer to set the unit to a fixed firing rate for the purpose of combustion analysis. The delay sets the length of time the boiler will stay in the service mode if no keys have been pressed before going back to its original state. This parameter can be changed by accessing parameter 4AP. The time range of this parameter is 0 minutes to 40 minutes. The default value is 20 minutes.

Tank setpoint temp

This setting is applied to the tank sensor (when connected). It is used to start and stop the HW call for heat. This setting can be changed by accessing parameter 4AS. The temperature range is 60°F (15.5°C) to 190°F (87.5°C). The default setting is 120°F (49°C).

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