Lennox EL195UHNE Series Manual page 43

Troubleshooting Poor Ignition or Combustion Resonance Issues
Check Air Orifice
See Figure 55.
Check the following
1-Does the unit have the correct
air orifice size? See table 19.
2 -Is the orifice fully seated tight
against the elbow ?
3
way?
4 - Is the air inlet screen clear of
any obstruction ?
Correct any problems found.
Is ignition or resonance issue
resolved ?
Check Gas Manifold Pressure
Gas manifold pressure within
range shown in table 18?
Check signal Pressure
Signal pressure within
range shown in table 18?
Check the following
1-. Vent /air intake pipe restriction.
2- Plugged drain
3- Plugged air inlet screen
4 - Signal hoses to gas valve
for kinks, loose fit or plugging.
Correct any problems found.
Manifold pressure correct ?
Yes
Is ignition or resonance
issue resolved?
Replace air orifice.
see table 19.
Yes
No
Yes
No
Yes
No
No
Yes
No
FIGURE 57
Page 43
Troubleshooting is complete
Replace air orifice.
see table 3.
Replace gas valve
Replace gas valve
Troubleshooting is complete