Install Instructions

73
11 Operating information (continued)
Installation & Service Manual
Space heat temperature regulation
Operating temperature (target)
The boiler control module senses water temperature and
regulates boiler firing rate to achieve a target temperature.
The target temperature is calculated as described in this
section under "Outdoor Reset Operation" when the outdoor
sensor is connected. The maximum target temperature
can be limited by the installer using the MAX SH SETPT.
This temperature can be set between 32°F and 190°F. If the
outdoor sensor is shorted or not properly installed, the target
temperature is fixed at the SH SETPT (Cold Day).
High limit operations
The Noble Fire Tube is equipped with an adjustable automatic
reset high limit and a manual reset high limit. 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.
Low water cutoff protection
1. The boiler control module uses temperature sensing of
both supply and return ports 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 (100208652).
FIRE TUBE
™
Low voltage blocking
The blower and gas valve require a minimum amount of
voltage in order to operate properly. If an ignition attempt is
made when the line voltage is temporarily low (such as during
a brownout), the control could enter a manual reset lockout.
To prevent this, the control monitors the voltage and blocks
any heat demands until the voltage returns to an acceptable
level.
Monitor external limits
Connections are provided on the connection board for
external limits such as a low water cutoff and AUX limit. The
boiler control will shut off the burner and inhibit relighting
whenever any of these external limits open.
Error logging
The control will hold the last 10 lockouts in memory. The
date and time of the occurrence will be recorded as well. Only
the 10 most current occurrences will be held in memory.