Install sidewall vent termination

What is going on

Field-supplied sidewall termination. Heights and spacing matter. Get them wrong and you get blocked pipes, recirculated flue gas, or frozen terminations in winter.

Likely causes

• Termination too close to grade or snow level
• Exhaust and intake ends too close together, recirculating flue gas
• Exhaust extension past the wall too long
• Unsupported run-up pipe sagging
• Uninsulated pipe in cold space

Check in this order

1. Route intake and exhaust so the termination is at least 12 in above grade or average snow level.
2. Keep exhaust pipe straight out or up as shown. Size it per Table 6.
3. Limit exhaust extension to 12 in for 2 in PVC or 20 in for 3 in PVC past the wall.
4. Keep at least 8 in between exhaust and intake ends (6 in with termination elbow).
5. Support run-up pipe every 24 in. Use two supports if extension is over 24 in.
6. Insulate with 1/2 in Armaflex where piping passes through unconditioned space, if required.
7. Seal the wall penetration and check for gaps around the pipes.
8. After startup, look at the termination during a call for heat to confirm clean exhaust.

More furnace guides

• Annual planned service inspection
• Annual service checklist
• Blower access panel and carbon monoxide hazard
• Burner assembly cleaning
• Change blower speed tap
• Check temperature rise and adjust blower speed