Carrier OBL098, Installation Instructions Manual

9

3 OPERATION 

3.1 START-UP 

Before starting up the unit, be sure to check that the following 
items are in compliance: 

1. 

The electrical installation, the oil supply system, the 
venting system, combustion air supply and ventilation; 

2. 

The blower access door is in place and the blower rail 
locking screws are well tightened; 

3. 

The Blocked Vent Shut-Off (BVSO) is installed according 
to instructions (for chimney venting); 

4. 

The oil supply valve is open; 

5. 

The burner ‘’Reset’’ button is well pushed in or re-armed; 

6. 

The preliminary air adjustments

on the burner

 comply 

with the technical specifications in this manual; 

7. 

The blower speed adjustments for heating and air 
conditioning are appropriate and according to the 
specifications in this manual; 

8. 

The blower start/stop delays are satisfactory; 

9. 

The thermostat of the room is in the heating mode and is 
set higher than the ambient temperature. 

To start the unit, turn the main electrical switch on. operating 
sequence oil heating mode 

3.2 

OPERATING SEQUENCE OIL HEATING 
MODE

1.  The W-R contact closes; 
2.  The burner motor starts up to pre-purge the combustion 

chamber for a period of 10 to 15 seconds. During that time 
a spark is established on the electrodes; 

3.  The solenoid valve opens and a flame is established. 

Shortly after, the electrodes cease to spark; 

4.  Then the blower runs up to full speed. The delay depends 

on the adjustments that were made on the electronic 
board, which controls the blower motor. Refer to Sections 
2.11 and 2.12, as well as the CFM tables 8 and 9 for more 
details. 

5.  When the call for heat is satisfied, the solenoid valve 

closes, the flame goes out and the burner motor stops 
(after post purge delay, if applicable). 

6.  The blower stops shortly after the burner. The delay 

depends on the adjustments that were made on the 
electronic board that controls the blower. Refer to 
Sections 2.11 and 2.12, as well as the CFM tables 8 and 9  
for more details. 

Note: A detailed operating sequence of the oil burner is 
outlined in the instructions provided with the burner. 

3.3 

CHECKS AND ADJUSTMENTS 

3.3.1 

P

URGING THE OIL LINE

Open the bleed port screw and start the burner. Allow the oil to 
drain into a container for at least 10 seconds. The oil should 
flow absolutely free of white streaks or air bubbles to indicate 
that no air is being drawn into the suction side of the oil piping 
and pump. Slowly close and tighten the bleed screw. Once 
closed, the flame will light up. 

3.3.2 

P

RESSURE ADJUSTMENT

The oil pressure must be adjusted according to the 
Technical Specifications of this manual. An adjustment 
screw and a connection for a pressure gauge are located 
on the oil pump for that purpose. Also refer to the burner 
instruction manual. 

3.3.3 

C

OMBUSTION 

C

HECK

CAUTION

The heat exchanger metal surfaces may have oil and the 
baffle insulation also contains binders. These products will 
burn or evaporate when the unit operates for the first time. 
Because of that, the smoke reading may be skewed 
during the first minutes of operation. Therefore, the unit 
must operate during at least 60 minutes before taking any 
readings to adjust the combustion quality. Let the unit cool 
down before making any adjustments. 

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 

D

RAFT 

R

EGULATOR 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.