Condensate Management Options for Amana/Goodman 90%+ AFUE Furnaces

Condensate Management Options for Amana/Goodman 90%+ AFUE Furnaces

by HVAC Distributors

Daikin has released Technical Service Bulletin TSB C-FN-0046 regarding condensate management for flue vents and intake piping on 90%+ AFUE condensing furnaces.

From Daikin:

For furnace installations with long runs of minimally sloped horizontal exhaust pipe, it is important to take the following precautionary steps to help ensure excessive condensate does not flow into the inducer housing or leak out of the assembly into the vestibule compartment.

  1. Verify exhaust pipe is sloped no less than ¼ inch per foot.
  2. Ensure drain coupling is positioned on the flue pipe adapter so the lower drain port is vertical and not sloped left or right.
  3. Verify clamps within drain coupling assembly are properly positioned and tightened according to Figure 1 below.

Figure 1

If condensate issues persist, the RF000142 coupling, as shown in Figure 2 on previous page, can be installed on the flue vent and/or intake pipe. If the RF000142 coupling is installed on flue vent and/or intake pipe, the arrow on the coupling must be pointing up or against the flow of water for proper drainage. A field supplied “T,” as shown in Figure 3, or a field supplied “Y,” as shown in Figure 4, installed in the flue vent and/or intake pipe is also an acceptable method of condensate management. Installation of a field supplied “T” or “Y” must include a drain trap and a proper condensate disposal location. If the furnace environment has the potential of freezing, the drain trap and drain line must be protected. The use of accessory drain trap heaters, electric heat tape and/or RV antifreeze is recommended for these installations.

Figure 3/4

If you have technical questions, please contact our Technical Support team.