Variable Speed Air Handler Instructions(continued). . .
Page 5 of 5 Document #1200365 Rev 10
09/04/2020
PLUMBING
Installation of the water coil plumbing should be
completed in a manner similar to the design shown
in Typical System Plumbing Diagram (Figure 14).
Standard copper pipe size 3/4".
Dedicated pump (circulator) to feed the water
coil and provide comfort modulation. Steffes
recommends a Taco 007 single speed 115
VAC pump (Order Item #1100002) or equal.
Maximum recommended water temperature
(as set in C011) is 180ºF/82ºC and the
minimum recommended water temperature (as
set in C012) is 150ºF/65ºC.
Pump serving the air handler is powered with
the black and white wires found in the junction
box on the lower left side of the Comfort Plus
Hydronic system. Refer to the Plumbing
Section of the Comfort Plus Hydronic Owner’s
and Installer’s Manual for more information.
Area in front of the air handler must remain
open for accessing the blower, filter, and coils.
NOTE: It is the responsibility of the installer to prevent involuntary flow of the water to the air
handler. Not doing so may cause limit tripping or decreased heat pump efficiency. Use of a
check valve, zone valve, etc. may help in this situation.
PLUMBING
The Air Handler filter should be replaced on a regular basis and general cleaning of the cabinet should be
conducted at the user’s discretion. No additional routine maintenance is required. Replacement filters can be
ordered from the factory (Order Item #1159017 for ½ HP and #1159063 for ¾ or 1 HP).
If utilizing a heat pump or air conditioner with the air handler, follow the manufacturer’s cleaning
recommendations for those devices.
WARNING
Risk of personal injury or property damage. Water
temperatures used for the Air Handler may not be
acceptable for other heating zones in the installation.
It is the responsibility of the installer to ensure that
proper tempering devices are in place.
FREEZE PROTECTION: Risk of frozen pipes. Can
cause property damage. Hydronic heating system
freeze-ups WILL cause extensive damage to the
entire heating system and/or property. Damage to the
air handler piping system can occur in low ambient
temperatures conditions or can be caused by a
system malfunction during air conditioning mode. It
is the responsibility of the installer to protect against
freezing of all plumbing and water coils.
PIPING SUPPORT: Risk of exchanger damage. Can
cause property damage or personal injury. DO NOT
use the exchanger as support for piping. Support
brackets should be in place to ensure proper
operation of the system and to keep pressure off the
inlet and outlet piping.
5100 Air
Secondary Loop
Low Temp Radiant Zones
White
This Valve Must
Be Open During
Normal Operation
Hydronic
Exchanger
