Thermo Pride PGL20-180, Installation And Service Manual

Page: 16 / 38

All installations and services must be performed by qualified service personnel.
14
Furnace Model Orifice Size Manifold Gas Pressure No. Turns Closed*
** PGL16-160 Nat #J (.277) 2.4” W.C. 24
PGL16-160 LP #8(.199) 2.9” 24
PGL20-180Nat #J(.277) 3.0” 20
PGL20-180 LP #3(.213) 3.0” 20
AGL16-160LP #8(.199) 2.9” 24
AGL20-180Nat #J(.277) 3.0” 20
AGL20-180LP #3(.213) 3.0” 20
*Air Adjustment screw: Number of turns closed from the
fully open position.
** PG-160 or PG-180 Power Gas Conversion Burners- use chart for applicable settings.
4. Attach a manifold pressure gauge (Inches of W.C. scale) to the outlet of the gas valve.
5. Turn on the furnace and adjust the manifold pressure to the setting indicated above for the desired rate and
orifice which applies to the unit being tested.
6. Let the furnace run until warm, approximately 10 minutes. Note: If the furnace required cleaning, you may
wish to allow any residual dust or soot to burn off before taking measurements.
7. If the draft exceeds the recommended maximum of .1”, a draft regulator should be used to reduce the draft to
the recommended parameters of –01 W.C. to –1” W.C.
8.
IMPORTANT: An accurate CO
2
or O
2
combustion analyzer is required when setting combustion. A carbon
monoxide detector capable of measuring flue gas down to 50 PPM of CO is also required. After the unit has
operated a minimum of 10 minutes and a proper draft is established-between-.01” W.C. and -.1” W.C., perform
a combustion test and make final adjustment to the combustion air to achieve the CO
2
or O
2
as listed below.
NATURAL GAS
MIN. MAX.
CO
2
7.0% 11.0%
O
2
2.0% 8.9%
CO <50 PPM
L.P. GAS
MIN. MAX. ** See
CO
2
8.0% 10.4% Note Below
O
2
5.5% 8.9% **See Note Below
CO <50PPM
DRAFTOVERFIRE
MIN. .MAX.
-.01 -.1
**Note!! Under absolutely no circumstances should the air adjustment screw (on LP units only) be closed more than
the number of turns indicated by the chart on the previous page.
9. Once the CO
2
or O
2
is adjusted to the above parameters, a Carbon Monoxide test must be done to insure less
than 50 PPM in the flue gas .
Any sign of soot or carboning during combustion indicates that there is insufficient primary air and the air shutter
should be opened more until this condition is corrected. If soot or carboning of the burner is suspected, a smoke
sample should be taken after the burner operates a minimum of 10 minutes. This would typically only occur in the
LP units. Opening the air adjustment screw should reduce the carboning from the combustion process.