Johnson Controls TM9V*MP installation manual UIM-C-0712, Condensate Drain Termination

701379-UIM-C-0712

It is possible for condensation to form inside the combustion air (intake) pipe in the summer months if significant length of combustion air pipe passes through conditioned space. This problem can be averted by the addition of a simple drain tee, or a drain tee with a drain on the combustion air pipe as close to the furnace as possible, as shown in Figure 23. This is true for all long horizontal venting in any furnace configuration. This will prevent the condensate from entering the furnace.

Exhaust Pipe

Combustion Air Pipe

Tee with Drain Trap

Trap

Connect to Drain

FIGURE 23: Typical. Combustion Pipe Drain Tee

CONDENSATE DRAIN TERMINATION

A condensate sump pump MUST be used if required by local codes, or if no indoor floor drain is available. The condensate sump pump must be approved for use with acidic condensate.

DO NOT terminate the condensate drain in a chimney, or where the drain line may freeze. If the drain line will be exposed to temperatures below freezing, adequate measures must be taken to prevent the drain line from freezing. Failure to provide proper protection from freezing can result in improper operation or damage to the equipment and possible property damage. When exposed to temperatures below freezing, use of a 3 to 6 watt per foot at 115 VAC, 40°F (4.4°C) self-regulating, shielded and waterproof heat tape is recommended on the drain line outside the furnace.

DO NOT trap the drain line at any other location than at the conden- sate drain trap supplied with the furnace.

Liquid anti-freeze will cause damage to internal plastic parts of this furnace. DO NOT attempt to winterize the furnace using liquid anti-freeze.

18 Johnson Controls Unitary Products