Lennox International Inc. GWB9-050IH-2 사용자 설명서

This section provides a brief description of the key controls 

and accessories found in this boiler.
See  Figure 26, Page 41  for detailed sequence of operation. 

See the Repair Parts Manual for locations of all control 

components and accessories described.

Integrated Boiler Control (IBC) is a microprocessor based 

controller for high effi ciency gas boiler that monitors 

all safety controls and which controls operation of the 

combustion air blower, circulator pump, burner, and 

a combination direct spark igniter/fl ame sensor. This 

controller is not intended for use with a vent damper. 

Controller is mounted on control panel inside of boiler and 

contains a three character user interface display.

High Limit Control determines maximum boiler water 

temperature and also provides means for protecting boiler 

and heating system from unsafe operating conditions which 

could damage boiler. 
Limit control sensor is mounted in ¾” NPT control well on 

top of the front boiler section at hot water outlet. 
Limit control is incorporated in IBC and is fi eld adjustable 

between 80°F and 190°F. 
Field setpoint adjustment for each installation depends on 

heating system requirements. 
Limit Control automatically resets when boiler water 

temperature decreases (10-30°F adjustable differential). 
Differential can be adjusted to provide fl exibility for boiler 

operation. Larger the differential, longer run cycle of boiler.

Thermal purge feature complies with 2012 DOE 

and NRCan requirements that boiler control must 

incorporate automatic means to adjust water 

temperature.

Intent of thermal purge is to insure usable residual 

heat in the boiler is circulated until it is suffi ciently 

depleted from the system before the burner is allowed 

to fi re.  To that end, on call for heat, burner is held 

off while circulator runs until boiler temperature drops 

to thermal purge temperature limit or time delay is 

exceeded. Both of these parameters are adjustable.

When boiler temperature falls below thermal purge 

temperature limit or time delay expires, burner is 

allowed to fi re.

In addition to thermal purge temperature and thermal 

purge time delay parameters, two other conditions release 

integrated boiler controller from thermal purge and allow 

burner to run in order to maintain comfort in the space.

• Boiler temperature has dropped 10°F from boiler water 

temperature measured at beginning of the call for heat.

• Boiler temperature is cooling at a rate greater than 

5°F/minute while circulator is running.

Depending on the specifi c installation, thermal purge 

delay might or might not affect end user’s expectation for 

domestic hot water delivery. In event the customer has a 

concern that it takes too long for hot water, the situation 

may be resolved in three ways.

A.  Add a Domestic Hot Water Module, ECR part 

Number 240009562 (Honeywell part number 

W8375s1008). This control senses when hot water 

is being drawn, and instructs the integrated boiler 

control to bypass the thermal purge operation until 

domestic how water draw ends. Thermal purge will 

then be re-enabled.
DHW module incorporates a temperature sensor 

installed at the indirect water heater’s hot water 

supply fi tting ( Note - this sensor is in addition to, 

not in place of, the limit control on the hot water 

tank.) The Module is connected to the Enviracom 

terminals in the Integrated Boiler Control.

B.  Thermal purge parameters may be adjusted (higher 

thermal purge temperature limit and/or shorter 

thermal purge time delay) to bring the burner on 

sooner.

C.  Thermal purge function can be disabled.

Electrically controlled Combination Gas Control Valve is 

designed to meet requirements for use with direct ignition 

systems found in this boiler. Valve is piped to gas/air mixer.

Direct spark igniter utilizes a spark gap to initiate gas 

combustion in the burner. Igniter is mounted next to burner 

through gas/air mixer. The igniter also serves as means for 

proving main burner fl ame by fl ame rectifi cation. In the 

event of a lack of fl ame signal on three (3) consecutive tri-

als for ignition, IBC will lockout and display Error Code 62. 

Draft Inducer Temperature Safety Switch is a disc 

thermostat (180 °F setpoint) located on induced draft fan 

outlet port. Switch protects inducer and vent pipe from 

potential high temperature condition for discharging fl ue 

gases. Condition would typically be result of higher high 

limit control setting or over fi ring. Temperature safety 

switch automatically resets when the vent temperature 

decreases. (15 °F switch differential).