Goodman Furnace: Horizontal installation: suspension, leveling and drain
Horizontal installation: suspension, leveling and drain on a Goodman furnace: Horizontal furnaces need proper support, a level end-to-end set-up with a slight forward tilt, and a trap drop for condensate. Crawl space units must be suspended from floor joists or set on a concrete pad.
Applies to: Horizontal installations
Common causes of horizontal installation: suspension, leveling and drain
- Furnace sagging or sloping backward, so condensate does not drain
- Drain trap too close to the furnace bottom
How to fix horizontal installation: suspension, leveling and drain: step by step
- If suspending from rafters or joists, use 3/8 in. threaded rod and 2 x 2 x 1/8 in. angle iron as shown in the figure.
- Crawl space: suspend from the floor joist or support on a concrete pad. Never set it on the ground or let it sit in water.
- Level the furnace from end to end with a slight forward tilt so the access doors sit about 1/2 to 3/4 in. lower than the back panel.
- Mount the condensate trap to the side panel with at least 5 1/2 in. of clearance below the furnace.
- Slope the drain line down from the trap to the drain point.
- Protect the trap and drain line from freezing if they are exposed to near-freezing temperatures.
If the unit shows an error code, look it up: Goodman Furnace codes
Source: Goodman GMVC96 service and troubleshooting manual, pp. 9-10. Written in our own words as a summary; always check the original manual.
General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.