10
CAUTION
Low flue gas temperature increases the risk of
condensation. Adjust the total flue gas temperature
at or higher then 204°C (400°F) in order for the heat
exchanger warranty to remain in force.
IMPORTANT
The combustion check verification MUST be performed after
the nozzle replacement or the burner cleaning. After these
manipulations, the combustion parameters are necessarily
modified. Refer also to the burner instruction manual.
1.
Pierce a test hole in the flue pipe, approximately 18 inches
from the furnace breech. Insert the smoke test probe into
the hole. For installation using a sidewall venting, use the
orifice provided on the breech plate;
2.
From a cold start, let the unit operate for about 5 minutes;
3.
Set the burner air setting until you have between 0 and 1
on the Bacharach Scale (or a ‘’trace’’);
4.
Take a CO
2
sample at the same test location where the
‘’trace’’ of smoke reading was taken and make note of it.
Example: 13.8% of CO
2
or 2.5% of O
2
;
5.
Adjust the burner air setting to obtain a CO
2
reading 1.5%
lower (or a O
2
reading 2.0% higher) than the reading
associated with the ‘’trace’’ of smoke. Example: 12.3% of
CO
2
or 4.5% of O
2
;
6.
This method of adjusting the burner will result in clean
combustion (Bacharach smoke scale between 0 and a
trace) and ensure the proper functioning of the system.
The optimum CO
2
level is around 12% to 13% (or 3.5% to
5.0% of O
2
).
3.3.4
Draft Regulator adjustment
On chimney installations only, a barometric draft regulator
(supplied with the furnace) must be installed, in order to ensure
proper draft through the furnace. The barometric damper must
be mounted with the hinge pins in a horizontal position and the
face of the damper vertical for proper functioning (see
instructions included with the damper.) After the furnace has
been firing for at least five minutes, the draft regulator should
be set to between -0.025" and -0.060" W.C.
3.3.5
Overfire pressure test
The overfire draft that is taken through the observation port,
located above the burner, is a measurement necessary to
determine if there is a blockage in the heat exchanger or the
flue pipe. Refer to the Technical Specifications in this manual
for overfire pressure values. A high pressure condition may be
caused by excessive combustion air, due to the air band being
too wide open, or a lack of flue draft (chimney effect) or some
other blockage, such as soot in the secondary section of the
heat exchanger or the use of an oversize nozzle input or high
pressure pump.
3.3.6 Vent Temperature Test
1.
After having adjusted the burner combustion, insert a
thermometer into the test hole in the breech pipe;
2.
The total vent temperature should be between 204 and
302°C (400 and 575°F). If not, check for improper air
temperature rise, pump pressure, nozzle size or a badly
sooted heat exchanger. Also refer to section 2.5 for
proper flue pipe sizing.
3.3.7 Supply Air Temperature Rise Test
1.
Operate the burner for at least 10 minutes;
2.
Measure the air temperature in the return air plenum;
3.
Measuring the air temperature in the largest trunk
coming off the supply air plenum, just outside the
range of radiant heat from the heat exchanger. 0.3 m
(12") from the plenum of the main take-off is usually
sufficient;
4.
The temperature rise is calculated by subtracting the
return air temperature from the supply air
temperature;
5.
If the temperature rise is lower or exceeds the
temperature specified in Table 1, p. 13, change to the
next lower or higher blower speed tap, until the
temperature rise falls to the target. If the excessive
temperature rise cannot be increased or reduced by
changing fan speed, investigate for ductwork
obstructions, dirty or improper air filter, improper firing
caused by improper pump pressure or nozzle sizing.
3.3.8 Limit Control Check
After operating the furnace for at least 15 minutes, restrict
the return air supply by blocking the filters or the return air
register and allow the furnace to shut off on High Limit.
The burner will shut off but the blower will continue to run.
Remove the obstruction and the burner should restart
after a few minutes. The time required for the restart also
depends on the adjustment of the blower “OFF” delay.
3.3.9 Restart after Burner Failure
1.
Set the thermostat lower than room temperature;
2.
Press the reset button on the burner primary control
(relay);
3.
Set the thermostat higher than room temperature;
4.
If the burner motor does not start or ignition fails, turn
off the disconnect switch and CALL A QUALIFIED
SERVICE TECHNICIAN.
CAUTION
Do not attempt to start the burner when excess oil has
accumulated, when the furnace is full of vapour or when
the combustion chamber is hot.
Summary of Contents for OLR112A16A
Page 18: ...18 Figure 2 Dimensions de la fournaise...
Page 19: ...19 Figure 3 Diagramme lectrique Moteur 4 vitesses PSC...
Page 20: ...20 Figure 4 Diagramme lectrique Moteur vitesse variable ECM...
Page 21: ...21 COMPOSANTES ET PI CES DE REMPLACEMENT...
Page 22: ...22 LISTE DE PI CES Avec moteur 4 vitesses PSC B50093B...
Page 24: ...24 LISTE DE PI CES Avec moteur vitesse variable ECM B50094B...
Page 41: ...16 Figure 2 Furnace dimensions...
Page 42: ...17 Figure 3 Wiring Diagram 4 Speed Motor PSC...
Page 43: ...18 Figure 4 Wiring Diagram Variable Speed Motor ECM...
Page 44: ...19 COMPONENTS AND REPLACEMENT PARTS...
Page 45: ...20 PARTS LIST With 4 speed motor PSC B50093B...
Page 47: ...22 PARTS LIST With variable speed motor ECM B50094B...
