SECTION 7: O
PERATION
AND
M
AINTENANCE
17
SECTION 7: OPERATION AND MAINTENANCE
The CTHN-Series series heater is equipped with a
direct spark ignition system.
7.1 Sequence of Operation
1. Turn the thermostat up. When the thermostat
calls for heat, the pump will start immediately.
After a small delay, the burners will begin their
ignition sequence, 45 seconds later, sparking
will begin at the electrode. Upon sparking of the
electrodes, the gas valve is energized.
2. The flame will be sensed by the flame sensing
rod and the electrode is de-energized.
3. If a flame is detected, the gas valve remains
open. When the call for heat is satisfied, the
burner shuts off. On CTHN-Series systems
equipped with the optional ROBERTS
GORDON
®
controllers, the pump will continue
operation for a post-purge period of two
minutes.
4. If no flame is detected, the gas valve is closed
on the module and a purge period begins. After
the purge, the module sparks, and there is a
second trial for ignition. If flame is still not
established, a third purge, and trial cycle begins.
After 3 trials, the module will lockout until reset.
Reset is accomplished by removing power from
the module for at least 5 seconds (thermostat
cycle required).
7.2 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.
7.3 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.
7.4 Pre-Season Maintenance and Annual Inspection
To ensure your safety and years of trouble-free
operation 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.
Disconnect 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
inspection of the heater.
For best performance, the gas, electrical, thermostat
connections, tubing, venting, suspensions and
overall heater condition are some of the areas
requiring inspection.
NOTE:
Gas flow and burner ignition are among the
first things that should be inspected.
Please
see Page 18, Section 7.5
for suggested items
to inspect.
