Service manual

23
10 PILOT AND MAIN BURNER
FLAMES
10.1. MAIN BURNER
The main burner, figure 14 should display the
following characteristics;
• Acceptable CO and CO
2
levels for
complete combustion.
• Light off smoothly.
• Reasonably quiet while running.
• Stable flame with minimum of lifting.
• Blue flame with natural gas, yellow tips
with propane gas
Figure 14 - Burner
If burner characteristics do not match the above,
check for proper air box pressure. Look for
accumulation of lint and other foreign material at
fan air inlets.
Table 11 – Typical air box settings
MODEL
AIR BOX “ W.C. (with burner firing)
Burner
#1
Burner
#2
Burner
#3
Burner
#4
2000 1.9
(2.2)
1.9
(2.2)
2500 1.5
(1.8)
1.5
(1.8)
1.5
(1.8)
3000 1.9
(2.2)
1.9
(2.2)
1.9
(2.2)
3500 1.6
(1.9)
1.6
(1.9)
1.6
(1.9)
1.6
(1.9)
4000 1.9
(2.2)
1.9
(2.2)
1.9
(2.2)
1.9
(2.2)
MODEL
FLUE SWITCH RECYCLE POINT “
W.C
Burner
#1
Burner
#2
Burner
#3
Burner
#4
2000 1.5
(1.9)
1.5
(1.9)
2500 1.1
(1.5)
1.1
(1.5)
1.1
(1.5)
3000 1.5
(1.9)
1.5
(1.9)
1.5
(1.9)
3500 1.2
(1.6)
1.2
(1.6)
1.2
(1.6)
1.2
(1.6)
4000 1.5
(1.9)
1.5
(1.9)
1.5
(1.9)
1.5
(1.9)
Depending on field conditions air box pressures
will have to be adjusted accordingly. Always set
the appliance for a CO
2
level in the range of
7.5% to 8.5 %. For a condensing appliance the
CO
2
level shall be in the range of 8.5% to 9.0%.
For Propane CO
2
level will be approximately
1.5% higher.
A qualified service technician should follow this
procedure when burner needs cleaning.
1. Shut off power and close main manual
gas valve.
• Allow burner to cool before removal.
2. Remove access cover screws.
• Disconnect pilot gas at bulkhead
fitting.
• Disconnect ground wire and ignition
wire.
• Remove nuts holding down burner.
• Gently pull down and forward to
disengage burner.