Patterson-Kelley Thermific, Installation & Owner'S Manual

Page: 18 / 46

Thermific
®
Gas-Fired Boiler Installation
Page 14
sure, water flow and temperature are satisfied, the
blower will run and pre-purge the boiler.
3. When air flow is established, the ignition trans-
former and pilot will operate. Both functions will
be indicated by separate green lights on the control
panel.
4. If a satisfactory pilot is established, the green "ig-
nite" light will extinguish and the pilot will remain
on, alone, for 10 seconds.
5. After 10 seconds, the green "Main Gas" light will
go on (the main gas valve will not open with the
wire disconnected and gas cannot flow to the
burner). The "Pilot" will remain on, along with the
"Main Gas", for another 10 seconds and then go
out. Since the main flame cannot be burning, at
this point there will be no flame signal and the
flame safeguard programmer will assume a
"Flame Failure" and will either re-cycle through
the complete pre-purge and ignition cycle or, if in-
surance or local codes require, go to a "lockout"
mode. Lockout will require manual reset of the
flame safeguard.
After completing this test, turn off the boiler and re-
connect the wire to the main gas valve.
3.11.2 Test of Low Water Cut-off
The boiler is furnished with a flow-switch-type low
water cutoff in the outlet nozzle. Test as follows:
Operation of the switch can be checked by first turning
the boiler off and then turning the system pump off,
stopping water flow in the system. After turning off
the pump, turn the boiler back on. It should not oper-
ate, and a red indicator for "Low Water" or "Water
Flow" should be illuminated. Do not shut the pump
off while the boiler is operating.
Perform appropriate tests on any external probe-type
low water cutoff.
3.11.3 Test of High-Limit Control
Fire the boiler and test the high limit control as fol-
lows:
With the main burner operating, turn down the tem-
perature setting on the "high-limit" thermostat until the
main burner shuts off. The high-limit switch must be
manually reset after testing. This check should also be
made for the "Operating Temperature" control (the
green "Heat" indicator will go out) (see next section
for Lo-Hi-Lo units). Readjust thermostats to desired
operating temperature and set high-limit temperature,
typically 20º F above operating temperature.
3.11.4 Test of Gas Pressure Switch
Manual Reset
Gas Pressure Switch
The boiler is furnished with a low gas pressure switch.
The operation of this switch must be checked by
slowly closing the main gas cock while the burner is
operating. The switch should shut down the main
burner. When the gas pressure switch opens, the "Low
Gas" or "Gas Press." indicator will light. Upon re-
opening the main gas cock, the "Low Gas" or "Gas
Press." indicator should remain on until the low gas
pressure switch is manually reset.