LAARS HEATING SYSTEMS
Page 16
2A. System Start-up
1.
Verify that the pump system is operating
properly:
a.
Shut off the manual gas valve located
outside the boiler.
b.
Raise the wall thermostat high enough to
call for heat.
c.
The pump should come on immediately. If
it does not, test the electrical circuits.
2.
Pilot and Main Burner Lighting:
a.
The JVH and JVP boilers do not require
manual lighting. The pilot is controlled by
the automatic ignition system.
b.
Different models of the JVi boiler utilize
various gas valves, (see Table 11).
Although the gas valves may have different
control knobs, they are all similar in
operation.
c.
Understand and follow the operating
instructions, on page 14, that are applicable
to the type of ignition system installed on
the boiler.
3.
The pilot and main burners will automatically
ignite when there is a call for heat.
2B. Sequence of Operation
1.
Wall thermostat will call for heat.
2.
Pump relay will turn on the circulating pump.
3.
If water temperature is below the limit setting,
the inducer motor relay will turn on the draft
inducer.
4.
Pressure switch will sense the fan (inducer)
operation and send 24 volts to the flame rollout
switch.
5.
In normal conditions, the flame rollout switch
will be in a closed position.
a.
JVH (Hot surface pilot ignition):
24 volts will be sent to the gas valve/
controller, the igniter will glow and the
pilot valve will open, lighting the pilot.
b.
JVP (Spark ignition):
24 volts will be sent to the ignition
controller, the igniter will spark and the
pilot valve will open, lighting the pilot.
6.
After pilot is proven to be lit, the main gas valve
will open, the main burners will ignite and
continue until either the hi-limit or wall
thermostat opens.
7.
When the wall thermostat is satisfied, the burners
will shut off. The relays will turn off the
circulating pump and the draft inducer. When the
room temperature falls below the wall thermostat
setting, the cycle will repeat.
Boiler
Size
Firing Systems
Natural or Propane
Valve
Number
Manufacturer
50-225
Hot Surface Pilot,
JVH
SV9500 &
SV9600
Honeywell
Spark Ignition,
JVP
VR8304
Honeywell
Table 11. Gas Valve Identification.
