HVACopediaTrane · Furnace troubleshooting
General venting requirements
What is going on
Furnaces are induced draft, Category IV, positive vent pressure. Vent must be gas tight and water tight.
Check in this order
- Vent the furnace to the outdoors. Do not connect it to any vent serving another appliance.
- Ship setting is direct vent with sealed combustion. Combustion air must come through the inlet pipe from outside air for direct vent.
- For nondirect vent (single pipe), combustion air may come from the surrounding area if combustion air requirements are met.
- Use 2 in, 2-1/2 in or 3 in plastic pipe (Table 10). Where venting goes through a masonry chimney that carries another gas appliance's flue products, or where local code requires it, use 3 in Type 29-4C stainless steel instead.
- Keep the snow clear from the vent area (building owner or maintenance provider responsibility).
- Make sure the vent system drains condensate and does not deteriorate.
Applies to: All UH1 and DH1 furnaces
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Source: Trane AUH1B080A9421B installer's manual, p. 18. Written in our own words; check the manual for your exact model.
For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.