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NTI · Boiler troubleshooting

Exhaust vent and intake pipe installation rules

TRX

What is going on

General rules for routing and joining vent pipe.

Check in this order

  1. Use only solid PVC, CPVC or stainless pipe, or polypropylene approved for Category IV. ABS is for air inlet only.
  2. Remove all burrs and debris from joints.
  3. Clean, prime and cement all PVC/CPVC joints with approved cement (ASTM D2564 for PVC, ASTM F493 for CPVC). Do not cement polypropylene.
  4. Slope horizontal exhaust back toward the boiler at least 1/4 in per foot.
  5. Support all piping. Use hangers at 4 ft intervals or less.
  6. Do not use the boiler to support any piping.
  7. Install roof flashing where pipe passes the roof.
  8. Keep the exhaust discharge pointing away from the roof pitch.
  9. Screen both terminations to keep out debris and birds.
  10. Do not vent over walkways, driveways or parking lots where condensate could freeze in cold climates.

Applies to: Exhaust vent and intake pipe

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Source: NTI TRX150 manual, p. 36-37. 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.