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Marvair GAA A/C w/Gas Heat I&O Manual
06/2023 Rev.5
holes with the silicone bead.
6. Using an appropriate and safe lifting device, set the unit on the bottom support bracket mounted on
the wall. You must stabilize the unit on the bracket with the lifting device or by some other means
- the bracket alone is not sufficient.
7. Make sure that the duct flanges are properly aligned with the wall opening. Adjust as necessary.
8. Note the holes in each side bracket. Using the holes for guides, drill holes through the wall with
a 3 / 8 inch drill bit. Insert the 3 / 8” bolts or lag screws through the brackets. Tighten the bolts to
secure the unit.
9. Apply a bead of silicone where the top flange and side brackets contact to the structure wall.
10. Fasten the top flange to the wall using #10 x 1 / 2 inch sheet metal screws.
11. On the inside of the structure, wall sleeves must be installed in the supply and return air openings.
The sleeves should be trimmed to fit flush with the inside wall.
12. Check the fit of each sleeve to its mating flange for possible air leaks. Apply silicone sealer to close
any gaps. Install the air return and supply grilles.
4.13 Gas Supply and Piping
WARNING
CARBON MONOXIDE, FIRE AND EXPLOSION HAZARD
Failure to follow safety warnings exactly could result in serious injury, death and / or property damage.
Models designated for Natural Gas are to be used with Natural Gas ONLY, unless properly converted to use
with LP gas.
AVERTISSEMENT
DANGER DE MONOXYDE DE CARBONE, D’INCENDIE OU D’EXPLOSION
Ne pas respecter exactement les AVERTISSEMENS de sécurité peut causer des dommages corporels graves
ou mortels et / ou des dégâts matériels.
Les modèles conçus pour du gaz naturel ne doivent fonctionner qu’avec ce gaz UNIQUEMENT, sauf s’ils ont
été convertis dans les règles pour utiliser du gaz propane ( LP ).
4.14 Gas Supply Requirements
• Use only the type of gas approved for this furnace. See rating plate for approved gas type.
• Gas input must not exceed the rated input shown on the rating plate. Overfiring will result in failure of
heat exchanger and cause dangerous operation.
• Do not allow minimum supply pressure to vary downward. Doing so will decrease input to furnace.
Refer to Table 4 for gas supply pressure. Refer to Section 6.2 Gas Manifold Pressure Adjustments.
Gas Type
Supply Pressure
Recommended
Max.
Min.
Natural
7”
14”
4.5”
Propane
11”
14”
11”
Table 4. Gas Pressures
4.15 Gas Piping Requirements
NOTE:
The gas supply line must be installed by a qualified service technician in accordance with all
building codes.
