This service bulletin describes the steps that may be necessary to replace your existing Model
ESU14 or ESU20 Steam Humidifier, with the new Model S2000 or S2020 Power Steam
Humidifier. The new “S” models have been redesigned and improved. There are some differences
which must be taken into account when installing this unit or replacing an older model.
1. MOUNTING -
First and most important is the mounting of the new humidifier. The new
model has a larger reservoir but measures the same width and height as the old “ESU”. The
reservoir protrudes deeper into the duct and occupies more space inside the duct. The new
“Under Duct Mounting Flange” is an integral part of the reservoir. As a result, the modification
to perform when mounting the new S2000 or S2020, is to snip and lengthen the flange dimension
on your existing reservoir cutout opening in the warm air supply plenum.
FIG. 4
MOUNTING TEMPLATE
MODEL S2000 & S2020
1. TAPE TEMPLATE IN LEVEL POSITION.
2. DRILL (8) HOLES FOR SHEET METAL SCREWS
SHOWN ON TEMPLATE (DO NOT DRILL LARGER
THAN 1/8" DIAMETER.
3. CUT OUT SOLID LINE AREA AS MARKED.
4. MOUNT HUMIDIFIER PER INSTRUCTIONS.
CUT ON LINE
CUT ON LINE
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P/N 094021B0037
With this modification done, you should be able to insert the new humidifier into the cutout
opening and secure the unit with the 8 self tapping screws provided. The hole dimensions on
the front plate have not changed and should match up. If necessary, locally reinforce the opening
with sheet metal sleeves to insure that the unit will remain level and not sag with the added
weight of the water.
1
A 2nd template is included with the “S” series humidifiers for mounting the unit under the duct
on the return or cold air side of the furnace. Note that there is no need to order an under the duct
mounting kit, due to the new integrated mounting flange.
Field Controls Humidifiers
AN-137 Replacement Instructions for
Models ESU14 & ESU20
SUPPLEMENT TO THE ELECTRONIC STEAM
POWER HUMIDIFIERS MODEL #S2000 AND S2020
P/N 090376A0137
REV. D 10/2011
Copyright © 2011, Field Controls Inc., All Rights Reserved
Field Controls Inc. 2630 Airport Road
Kinston, NC 28504
PH: 252.522.3031
FAX: 252.522.0214
