Modine Manufacturing PV Installation And Service Manual page 11

O O P P E E R R A A T T I I O O N N
L L i i g g h h t t i i n n g g I I n n s s t t r r u u c c t t i i o o n n s s ( ( a a l l s s o o o o n n u u n n i i t t ) )
F F o o r r u u n n i i t t s s w w i i t t h h s s t t a a n n d d i i n n g g p p i i l l o o t t
1. Set thermostat to lowest setting. Move gas control knob (or
lever) to OFF and wait 5 minutes.
2. Move gas control knob to pilot (or move gas control lever to
set) and depress reset button while lighting the pilot and
hold for 1 minute after pilot is lit.
3. Move gas control control knob (or lever) to ON.
4. Set thermostat to desired setting.
F F o o r r u u n n i i t t s s w w i i t t h h i i n n t t e e r r m m i i t t t t e e n n t t p p i i l l o o t t
1. Set thermostat to lowest setting. Move gas control knob (or
lever) to OFF and wait 5 minutes.
2. Move gas control knob (or lever) to ON.
4. Set thermostat to desired setting. (pilot and main burner will
light automatically when thermostat calls for heat).
S S h h u u t t D D o o w w n n I I n n s s t t r r u u c c t t i i o o n n s s
Turn off power and close all gas valves.
A A f f t t e e r r I I n n i i t t i i a a l l S S t t a a r r t t - - U U p p
1. Check pilot flame adjustment as discussed below.
2. Check gas piping for leaks with a soap bubble solution to
insure safe operation.
3. Check gas input rate, as described below, to assure proper
gas flow and pressure.
F F i i g g u u r r e e 7 7
C C o o r r r r e e c c t t P P i i l l o o t t F F l l a a m m e e
P P i i l l o o t t F F l l a a m m e e A A d d j j u u s s t t m m e e n n t t
The pilot is orificed to burn properly with an inlet pressure of 6-7"
W.C. on natural gas and 12-14" W.C. on propane gas, but final
adjustment must be made after installation. Adjust to have a soft
steady flame 3/4 to 1" long and encompassing 3/8-1/2" of the tip
of the thermocouple or flame sensing rod. Normally this flame will
produce satisfactory results. To adjust flame use pilot adjustment
screw on combination gas control (for location, see the
combination gas control literature supplied with unit). If the pilot
flame is longer and larger than shown by Figure 7, it is possible
that it may cause soot and/or impinge on the heat exchanger
causing burnout. If the pilot flame is shorter than shown it may
cause poor ignition and result in the controls not opening the
combination gas control. A short flame can be caused by a dirty
pilot orifice. Pilot flame condition should be observed periodically
to assure trouble-free operation.
N N a a t t u u r r a a l l G G a a s s F F l l a a m m e e C C o o n n t t r r o o l l
Control of burner flames on units utilizing natural gas is
achieved by moving the gas manifold to either increase or
decrease primary combustion air. Prior to flame adjustment,
operate unit with bottom pan closed for about five minutes.
Operation can be viewed through the viewing port on the rear of
the unit (see Figure 10).
Lack of primary air will cause soft yellow-tipped flames. Excess
primary air produces short, well-defined flames with a tendency
to lift off the burner ports. Proper operation with natural gas
provides a soft blue flame with a well-defined inner cone.
To increase primary air, lower the bottom pan (see Figure 1).
With the bottom pan lowered, loosen the manifold mounting
screws (see Figure 17) and tap the manifold away from the mixer
tubes until the yellow flames disappear. To decrease the primary
air, move the manifold closer to the mixer tubes until flames no
longer lift from burner ports, but being careful not to cause yellow
tipping. Retighten manifold mounting screws after adjustment.
Once adjustment has been made, close the bottom pan.
P P r r o o p p a a n n e e G G a a s s F F l l a a m m e e C C o o n n t t r r o o l l
Adjustable primary air shutters are attached to the orifices on
the gas manifold for units equipped for propane gas operation
(see Figure 19). A A n n o o p p t t i i m m u u m m f f l l a a m m e e w w i i l l l l s s h h o o w w a a s s l l i i g g h h t t y y e e l l l l o o w w t t i i p p . .
If flame adjustment is necessary, adjust the primary air
shutters. Loosen wing nuts and push shutters forward to reduce
primary air until yellow flame tips appear. Then increase primary
air until yellow tips diminish to just a slight yellow tip and a clean
blue flame with a well-defined inner cone appears.
It may also be necessary to adjust the manifold position in
addition to adjusting air shutters to obtain the proper flame.
Follow the instructions under "Natural Gas Flame Control" for
adjusting the manifold.
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C C A A U U T T I I O O N N
Check the gas inlet pressure at the unit upstream of the
combination gas control. The inlet pressure should be 6-7"
W.C. on natural gas or 12-14" W.C. on propane. If inlet
pressure is too high, install an additional pressure regulator
upstream of the combination gas control.
Important – Inlet pressure and manifold pressure must be
checked with unit in operation when making final adjustments.
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