Service manual

CTH2-SERIES INSTALLATION, OPERATION AND SERVICE MANUAL
42
SECTION 11: OPERATION AND MAINTENANCE
This heater is equipped with a hot-surface ignition
system.
11.1 Sequence of Operation
1. Turn the thermostat up. When the thermostat
calls for heat, the SmartValve
®
II will energize.
After a short period, power is supplied to the
blower motor.
2. When the motor approaches nominal running
RPM, the pressure switch closes and signals
the ignition module/SmartValve
®
II.
3. The ignition module/SmartValve
®
II then ener-
gizes the hot-surface igniter for a timed warm-up
period (approximately 45 to 60 seconds). After
the warm-up period, the gas valve is energized.
4. If a flame is detected, the gas valve remains
open and the igniter is de-energized. When the
call for heat is satisfied and the system control
mechanism de-energizes the burner line voltage
supply, the gas is turned off.
5. If no flame is detected by the flame sensing rod,
the igniter is de-energized and the module/
SmartValve
®
II will close and a purge period
begins. After the purge, the module/SmartValve
®
II acts to power the igniter for a second warm-up
period and a second trial for ignition period. If
flame is still not established, a third purge,
warm-up, and trial cycle begins. After four trials,
the module/SmartValve
®
II will lockout for one
hour or until reset.
6. If the flame extinguishes during operation, the
igniter module will provide multiple trial
sequences described in step 5. If ignition is not
re-established, the module/SmartValve
®
II will
lockout for one hour or until reset.
7. After lockout, reset by turning down thermostat
for five seconds, and then raising it again to
desired temperature, or by disconnecting power
and then reconnecting.
11.2 To Shut Off Heater
Set thermostat to lowest setting.
Turn OFF electric power to heater.
Turn OFF manual gas valve in the heater supply line.
11.3 To Start Heater
Turn gas valve and electric power OFF and wait five
minutes for unburned gases to vent from heater.
Turn ON main gas valve.
Turn ON electric power.
Set thermostat to desired temperature. Burner
should light automatically.
11.4 Pre-Season Maintenance and Annual
Inspection
To ensure your safety and years of trouble-free oper-
ation of the heating system, service and annual
inspections must be done by a contractor qualified in
the installation and service of gas-fired heating
equipment.
Turn off gas and electric supplies before performing
service or maintenance. Allow heater to cool before
servicing.
Before every heating season, a contractor qualified in
the installation and service of gas-fired heating
equipment must perform a thorough safety inspec-
tion of the heater.
For best performance, the gas, electrical, thermostat
connections, tubing, venting, suspensions and over-
all heater condition should be thoroughly inspected.
NOTE: Gas flow and burner ignition are among the
first things that should be inspected.
Please see Page 43, Section 11.5 for suggested
items to inspect.
WARNING
Turn off gas and electrical supplies before performing
service or maintenance.
Failure to follow these instructions can result in
death, injury or property damage.