Wiring
DO NOT short gas valve terminals. This will damage
the wall thermostat and void the warranty.
1. Check the system for the proper transformer by
comparing the volt amps (VA) ratings of the trans
former and the system. The system rating is
determined by
multiplying the
voltage draw x
the amp draw.
Normally 20VA
transformers
are
sufficient for
heating only applications
and
40VA for
heating/cooling
applications.
(Note: improper
transformer
VA rating will
cause erratic
system
operation).
2. Connect the
wire from
the “MV”
terminal on the ignition control unit to
the “M” terminal on the
gas valve.
3. Connect the wire from the “PV” termi-
nal on the ignition control unit to the
“P” terminal on the gas valve.
4. Connect the wire from the “MV/PV”
terminal on the ignition control unit to
the “C” terminal on the gas valve.
Hot Surface Applications: Pilot Tubing
Figure 5 shows the wiring and instructions
for hot surface ignition (HSI) applications.
The pilot plug must be in place
as there is no need for a pilot. It can be
either local sense using the igniter as a
sensor or remote sense with a separate
flame sensor. The instructions for pilot
tubing are as follows:
Typical Robertshaw Intermittent Pilot Application
Note: Some hot surface applications use the pilot outlet.
If so, proceed as directed below. If not used, install
pilot outlet tubing plug packaged in the 720-079 gas
valve kit, then proceed to “wiring.”
1. Make sure tubing is free of burns and dirt.
2. We strongly recommend that the pilot orifice be
checked and cleaned if necessary at this time.
3. Connect pilot tubing into the control using fitting
provided, and tighten for a gas-tight seal.
Gas/Propane Basics
and outlet pressure taps and the regulator adjustment
cap.
Figure 3 illustrates the capacities for different inlet
and outlet sizes for the 7200 series. The 720-079 as
shown in the ordering data is ½" x ¾" valve with a capacity
of 150,000 BTUs. The cross-references in Table
1 cover White-Rodgers and Honeywell Valves.
Figure 3
Figure 4
Intermittent Pilot: Pilot Tubing
Figure 4 illustrates the installation instructions and
wiring for intermittent pilot applications. The instructions
for pilot tubing are as follows:
1. Make sure tubing is free of burns and dirt.
2. The pilot orifice must be checked and cleaned if
necessary at this time.
3. Connect pilot tubing into the control using fitting
provided and tighten for a gas tight seal.
ICM/March/April 2021 17