Lochinvar 151-286 operation manual Boiler temperature regulation

Outdoor Knight Boiler Installation & Operation Manual

8 Operating information (continued)

Monitor external limits

Connections are provided on the connection board for external limits such as a flow switch, low water cutoff and gas pressure switches. The SMART SYSTEM will shut off the burner and inhibit relighting whenever any of these external limits open.

Run-time and alarm outputs

The boiler provides dry contacts for indicating when the boiler is running, and when it is unable to operate.

Run-time and cycle counting

The control uses two timers to monitor the total hours of burner operation. One timer monitors the time the boiler is firing in the Space Heating Mode. The other timer monitors the time the boiler is firing in the DHW Mode.

The control uses two (2) ignition counters to monitor the amount of boiler cycles. The first counter counts all ignitions of the control. The second counter counts only ignition attempts that have failed.

Service reminder

The control can be programmed for service reminder notification. This notification will become active when either a set time frame has expired, or a set amount of running hours or cycles has expired (all adjustable by the installer). The display will show a Maintenance Required screen. The installer's name and phone number can be programmed into the control. This information will appear on the Maintenance Required screen. The service reminder notification can be reset or disabled by the installer.

The time dependent feature has been disabled by the manufacturer. To enable this feature change the parameter to the desired time interval, reference the Outdoor Knight Service Manual for details regarding parameters.

Error logging

The control will hold in memory the last 10 lockouts as well as the last 10 blockings. The date and time of the occurrence will be recorded as well. Only the 10 most current occurrences of each will be held in memory.

Boiler temperature regulation

Operating temperature (target)

The SMART SYSTEM control module senses water temperature and regulates boiler firing and firing rate to achieve a target temperature. The target temperature can be set between 32°F and 190°F.

•Target temperature is calculated as described in the “Outdoor Reset Operation” section, when the outdoor sensor is connected.

•If the outdoor sensor is not connected, the target temperature is fixed at SH (1 - 3) set points. An outdoor sensor fault will remain on the display screen until the outdoor sensor is reconnected.

High limit operations

The outdoor boiler is equipped with adjustable automatic reset and manual reset high limits. The automatic reset high limit has a maximum set point of 200°F and the manual reset high limit has a maximum set point of 210°F.

When the outlet temperature exceeds 200°F, the automatic high limit action occurs. The boiler shuts down until the outlet water temperature cools below 190°F, and a 60 second timer has expired. If the outlet temperature continues to increase, the manual reset high limit action will occur at 210°F.

High limit test procedure

NOTICE	Please note that the brackets ([]) denote
	screen status.

1.Turn ON the main power to the boiler by placing the ON/OFF switch in the ON position.

2.From the Status Screen, press the NAVIGATION dial to access the Set Points Screen.

3.Press the LEFT SELECT (LIMITS) key.

4.Select the manual reset high limit (MRHL) by rotating the NAVIGATION dial counterclockwise, then press the NAVIGATION dial.

5.Decrease the set point of the MRHL to below the current outlet temperature (or to its minimum setting, whichever is higher) by turning the NAVIGATION dial counterclockwise.

6.Press the RIGHT SELECT [SAVE] key.

7.Press the RIGHT SELECT [HOME] key. The new parameter will upload to the control.

8.If the current outlet temperature is above the new MRHL set point, the MRHL will function causing boiler lockout. If this occurs, skip to Step 11.

9.If the current outlet temperature is below the new MRHL set point, locate the pinhole (SERVICE button) below the RESET button on the display board. Insert a thin probe (such as a paper clip) into the hole and press the button continuously for five (5) seconds to place the boiler into Service Mode. In Service Mode, the boiler will fire at ignition speed and will then modulate up to full fire.

10.Once the outlet temperature rises up to the MRHL set point, the MRHL will function, causing the boiler to shut down and lock out.

11.Repeat Steps 2, 3 and 4.

12.Set the MRHL to the appropriate set point by turning the NAVIGATION dial clockwise.

13.Repeat Steps 6 and 7.

14.Press the RESET button to clear the lockout.

15.If needed, press the RIGHT SELECT [STOP] key to exit Service Mode.

Low water cutoff protection

1.The SMART SYSTEM control module uses temperature sensing of both supply and return areas of the heat exchanger. If the flow rate is too low or the outlet temperature too high, the control module modulates and shuts the boiler down. This ensures boiler shutdown in the event of low water or low flow conditions.

2.Some codes and jurisdiction may accept these integral features of the control in lieu of requiring an additional limit control or low water cutoff. Consult local jurisdiction to determine. A low water cutoff is available from the factory (WTR30024).

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