— Screwdriver
—Wrench
— Pliers
— Shut-off water valve
— Water line (LDPE or Copper)
Humidifier Configuration
The HM700 is configured at the factory to operate under most
conditions without the need to change its configuration.
NOTE: Because the humidifier is factory configured for
INSTALLATION INSTRUCTIONS
optimal performance, Honeywell strongly
discourages changes to the jumpers or the
potentiometer; doing so will void the warranty
and could damage the humidifier. Contact
Honeywell Customer Care for further
information.
INTRODUCTION
The HM700 is the most advanced residential steam humidifier
available and provides steady and reliable humidification for a
home. The humidifier is designed for connection to a steam
distributor installed in a supply air duct for humidity on
demand.
IMPORTANT
Read and save these instructions. This guide should
be kept by the installer, and the Homeowner’s Guide
should be left with the equipment owner.
Included in the Box
— Steam Humidifier (HM700)
— Distribution Remote Mount Kit (HM700ADISTKIT)
— HumidiPRO Humidistat (H6062A1000)
— Steam Cylinder (one HM700ACYL2 included)
— Rubber drain hose
— Installation Instructions, Homeowner’s Guide and
Quick Start Guide
Table 1. Specifications.
Steam
Output
Part NumberVolts
HM700A1000
110/120111.4
220/240222.8
GPDKWAmps Phase
12.0115 ACYL2
Before Installation
1. Ensure that available voltage and phase corresponds
with humidifier voltage and phase as indicated on
humidifier’s specification label.
2. Ensure that the dedicated external fuse disconnect is of
sufficient size to handle the rated amps as indicated on
the specification label. Refer to local codes.
3. Ensure sufficient clearances will be available as
described in the Location section on page 5.
4. Ensure steam lines can be routed to duct distributor as
described in Steam Lines and Condensate Return
Instructions on page 8.
Dimensions
in inches
(L x W x H)
11.5 x 6.75 x 21.5
Max Ext
Fuse
Standard
Cylinder
Net/Full
Weight
lbs. (kg)
15 / 20
(7.0 / 9.5)
33-00118EFS-01
HM700A1000
CAUTION
CAUTION
CAUTION
CAUTION
CAUTION
M35758
Golden Valley Minnesota 55422
MADE IN CANADA
MODEL:
VOLTS 1:
KW:
HM700A1000
S/N:
XXXXXXX
110-120
PHASE:
1
HZ:
60
1.4
DATE:
XXXXXXXXX
2583297A
220-240
VOLTS 2:
F.L.A: GPD:
12.0
F.L.A: GPD:
12.0
2.9
KW:
Auto-Adaptive
11
22
1
LISTED 205X
HUMIDIFIER
Servicing
Disconnect main power before any servicing.
The plumbing and electrical compartments contain
high voltage components and wiring. Access should
be limited to authorized personnel only.
During and following operation of the humidifier, the
steam and components in contact with the steam
such as the steam lines, steam distributors, and
condensate lines can become hot and can burn if
touched.
Honeywell does not accept any liability for installations
of humidity equipment installed by unqualified
personnel or the use of
parts/components/equipment that are not
authorized or approved by Honeywell.
To maintain warranty, only Honeywell approved parts
and cylinders may be used in the operation of the
product.
Electrical
All electrical work should be done according to local
and national electrical code.
Electrical connection to be performed by a licensed
electrician.
Unit must be powered by a dedicated GFI circuit.
Plumbing
Plumbing to be performed by a licensed plumber.
Drain water from humidifier can be very hot. Do not
drain to public sink.
All plumbing work should be done according to local
plumbing code.
Fig. 1. Specification label location.
Installation
Do not mount on hot surfaces.
Do not mount in area where freezing can occur.
Do not mount on vibrating surface.
Do not mount on floor.
The HM700 produces steam at atmospheric pressure.
No devices which could block steam output should
be connected to the steam outlet.
Steam lines must be installed so that no restriction can
produce backpressure in the humidifier.
Water quality
The Honeywell HM700 requires a cold water
connection from your home's main water supply
between 30-100 PSIG. A throttle valve may be
necessary, and a water shut-off valve is
recommended for safety. Reverse Osmosis (RO)
and Deionized (DI) water must not be used. Water
conductivity is important to ensure the electrode
humidifier operates effectively. Honeywell
recommends 150-1200 μS (microsiemens).
Parts and Accessories
The following parts and accessories are available and may have been included with your HM700 humidifier. The cylinder is the
only item that will need periodic replacement to maintain proper humidifier operation.
Table 2. Parts and accessories.
Part/AccessoryPart Number
Replacement CylinderHM700ACYL2
HumidiPRO HumidistatH6062A1000
Stainless Steel Distribution Remote Mount KitHM700ADISTKIT
Replacement Drain ValveHM700ADVALVE
Replacement Fill ValveHM700AFVALVE
Replacement TransformerHM700ATX
Replacement PC BoardHM700APCB
15 ft. Insulated Steam and Condensate Line Hose KitHM700AHOSEKIT
33-00118EFS—012
Differential Pressure Switch for Air Proving50027910-001
How the Humidifier Works
The HM700 is an atmospheric steam generator that uses heat
generated by electrical current flowing between submerged
electrodes to generate steam. The HM700 is designed for ondemand air humidification via a steam distributor.
STEAM GENERATION
• Once the unit receives a demand signal and the safety loop
between terminal 1 and 2 is closed, the humidifier closes
the contactor and measures the electrical current.
• If the demand is lower than the actual output the inlet valve
is kept closed and output is reduced by letting the water
level in the cylinder decrease by evaporation.
• If demand is higher than the actual output, after a brief
delay the fill valve is activated and water flows into the fill
cup. Water from the fill cup flows into the bottom of the
cylinder through a hose connected to the drain valve
housing.
NOTE: The cylinder is gravity fed from the fill cup. If
backpressure from the steam line is too high it
will cause water to back up in the fill cup and
flow down the overflow line to the drain.
• As soon as the water in the cylinder comes in contact with
the energized electrodes, current flows through the water.
The resistance of the water to the electrical charge
generates heat and in turn steam. The electrical current
(and steam output) increases as the level of water
increases, as more of the electrode becomes submerged.
The unit continues to fill until the current matches demand
or the high water sensor detects a high water level.
• The HM700 repeats the fill and boil down cycle repeatedly
to match output to demand.
• Over time minerals in the water will adhere to the cylinder
electrodes. The humidifier will automatically fill to a higher
water level to maintain full capacity during the life of the
cylinder. Eventually because of scale formation it will no
longer be possible for the humidifier to reach its full
HM700A1000
capacity. The HM700 software monitors this condition and,
when detected, will stop operating and flash the yellow
LED in a repeating sequence of 4 flashes.
DRAINS
• As steam is produced, minerals are left behind, increasing
the conductivity of the water. The HM700 patented auto
adaptive cycle will monitor the water conductivity and
perform drains to maintain the water at optimal conductivity
for peak performance.
• The auto adaptive cycle ensures cylinder life is maximized.
It does this by keeping the tightest control and most
efficient use of water during the entire cylinder life.
STEAM DISTRIBUTION
Steam generated by the humidifier may be introduced into the
air in several different ways. The most common method for
adding the steam into the air is to mount a steam distributor
tube in a supply air duct.
STEAM LINE
The steam line between the cylinder steam outlet and the
distributor serves two purposes: it is used as a conduit to
transfer the atmospheric steam from the humidifier to the
distributor, as well as providing a means to remove
condensate. See “Steam Lines and Condensate Return
Instructions” on page 8 for information on selecting steam
lines.
CONDENSATE RETURN
Whenever steam is distributed condensate is formed in the
distribution system. Insulating steam lines is one important
way to reduce the amount of condensate formed. Steam lines
are sloped so that condensate does not collect in the lines and
create a restriction to steam flow. The condensate must be
collected and removed from the system so that it does not
build up and leak into the duct. Condensate can be returned to
the HM700 fill cup to reduce water waste or can be fed to
drain.
The HM700 should only be installed if it has been
sized properly. Do not use square feet when sizing a humidifier installation. Instead, cubic feet must
be used, since the humidity is filling a volume of
space (width x length x height). Also, take into
consideration the “tightness” of a home’s
construction.
Fig. 2. Typical HM700 Installation.
Measurements in inches (mm).
The HM700 produces 11 gallons per day (GPD) when run on
120 V and 22 GPD when run on 240 V. See Figure 16 for
details on configuring the HM700 to run on a different voltage.
Table 3 contains AHRI recommendations for humidity
requirements and Table 4 shows what humidifiers and output
configuration will satisfy the humidification requirements.
Table 3. AHRI Recommended Humidity (in gallons per day).
Construction
Type8,000 ft
Tight3.34.35.47.59.611.716
Average7.69.611.81620.324.433
Loose11.714.918.124.530.837.150
3
12,000 ft
3
16,000 ft
3
20,000 ft
3
24,000 ft
3
28,000 ft
3
32,000 ft
3
33-00118EFS—014
HM700A1000
INSTALL SECOND
SCREW AFTER
HANGING
HUMIDIFIER
#8 X 2 IN. (5 CM)
WOOD SCREWS
INSERT SCREW LEAVING
1/4 IN. (6 MM) EXPOSED.
HANG UNIT, THEN
TIGHTEN SCREW.
2X4 OR OTHER
STRUCTURAL
MEMBER
KEYHOLE
M35759
HOLE
Table 4. Steam humidifier(s) necessary for application.
Construction
Type8,000 ft
3
12,000 ft
3
16,000 ft
3
20,000 ft
3
24,000 ft
Tight11 GPD11 GPD11 GPD11 GPD11 GPD
Average11 GPD11 GPD22 GPD22 GPD22 GPD
11 GPD (x3)
Loose22 GPD22 GPD22 GPD
or
22 GPD (x2)
a
In the table above, 11 GPD indicates a steam humidifier configured to run on 120 V and 22 GPD indicates a steam humidifier
11 GPD (x3)
or
22 GPD (x2)
a
3
28,000 ft
11 GPD (x2)
22 GPD (x1)
11 GPD (x3)
22 GPD (x2)
11 GPD (x4)
22 GPD (x2)
3
32,000 ft
3
11 GPD (x2)
or
or
22 GPD (x1)
11 GPD (x3)
or
or
22 GPD (x2)
11 GPD (x5)
or
or
22 GPD (x3)
configured to run on 240 V.
LOCATION
NOTE: Do not mount on hot surfaces, where freezing
can occur, vibrating surface, or floor.
Mount on a suitable wall or vertical surface. Do not sit the unit
on the floor. Allow clearances required for plumbing and
electrical connections. Clearance dimensions shown are for
reference only and are the minimum required for maintenance
of the humidifier. Consult local and national codes before final
location and installation. Honeywell does not accept
responsibility for installation code violations.
• Install only in areas with ambient temperature 41 to 104 °F
(5 to 40 °C) and relative humidity 5 to 95 %.
• When possible install below the steam distributor. Take
care to provide proper steam line routing and proper
condensate traps.
• DO NOT locate the humidifier any further then absolutely
necessary from the steam distributor location as net output
will be reduced as a result of heat loss through the steam
line.
Mounting with Keyholes
1. The HM700 humidifier is wall mounted using a keyhole
located on the back of the unit cabinetry.
2. Use #8 x 2 in. (5 cm) screws mounted into 2x4 studs or
better. 2 screws are needed, one for hanging the unit
and one for securing so it will not lift off the keyhole.
3. Install the top screw so that 1/4 in. (6 mm) is exposed.
Raise the unit and place the screw head through the
keyhole.
4. Make sure the unit is level and then insert and tighten
the second screw through the bottom hole. Tighten the
top screw. See Fig. 3.
NOTE: Use screws longer than 2 in. (5 cm) if drywall or
other spacer is present.
• When possible, mount the HM700 humidifier at a height
convenient for servicing.
Fig. 3. Mounting with keyholes.
533-00118EFS—01
HM700A1000
M35855
PLUMBING
USE 1/4 IN. COMPRESSION
FITTING (INCLUDED) TO
CONNECT WATER SUPPLY
LINE TO UNIT (LDPE PLASTIC
WATER SHUT-OFF VALVE.
OR COPPER).
1/2 IN. (30 MM) OD
ALWAYS INSTALL A
1
FILL AND DRAIN LINES CAN ALSO BE
1
ROUTED THROUGH OPENING IN BACK
OF CABINET.
Fig. 4. Water supply and drain connection.
IMPORTANT
— All water supply and drain line connections should be
installed in accordance with local plumbing codes.
— Drain water is automatically cooled to 140 °F (60 °C)
when HM700 cycles a drain. When the manual drain
switch is used, temperature may be higher. The drain
material (tube and drain) must be rated for 200 °F
(93 °C).
• Supply water should be between 30 to 100 PSIG. A throttle
valve may be used if necessary.
• Do not use reverse osmosis or de-ionized water. Supply
water should be between 150-1200 μS (microsiemens) for
optimal conductivity.
USE 1/2 IN. OD COPPER TO
WITHIN 4 FT (1.2 M) OF HUMIDIFIER.
M35760
• Supply water should be cold, 34 to 68 ºF (1 to 20 ºC).
• Install water shut off valve before humidifier to facilitate
servicing.
• The drain line should not end in a sink used frequently by
personnel, or where plumbing codes prohibit it. Route to a
floor drain or equivalent for safety reasons.
• Drain line should be routed to allow free flow of water.
Ensure adequate slope, no traps, and no kinks. A restricted
drain can cause cylinder water to over concentrate and
result in poor operation.
• If a drain is not located near the humidifier use a
condensate pump rated for hot drain water.
Fig. 5.
33-00118EFS—016
Steam Distributor
M35766
AIR FLOW
The HM700 requires a steam distributor installed in the
supply-side of ductwork. The HM700 can distribute steam into
a ventilation duct using the distributor shown in Table 5.
Table 5. Steam distributor.
Part NumberDescriptionNotes
HM700ADISTKIT
1/3W
Stainless Steel Distribution
Remote Mount Kit
W
2/3W
1/3W
H
1/3W
Includes a steam distributor, 5 ft. insulated steam hose, condensate
hose, and installation hardware.
1/3W
The steam distributor should be installed as close as possible
to the humidifier. Short steam distribution lines minimize
condensate loss and the possibility of generating
backpressure in the steam distribution line.
Fig. 8. Distributor installed horizontally
HM700A1000
AIR FLOW
2/3
1/3
M35764
in a horizontal duct.
MIN. W=8 (203)
1
2
3
Fig. 6.
+45˚
1 TURN
–45˚
M35755
AIR FLOW
1/3
2/3
M35765
Fig. 9. Distributor installed horizontally in a vertical duct.
Rotate the distributor 45º so that steam is discharged
toward the center of duct, in the direction of the air flow.
Fig. 10. Distributor installed vertically in a horizontal duct.
This configuration is not recommended.
M35756
Fig. 7.
733-00118EFS—01
HM700A1000
M35761
SPRING CLAMP
3/8” OD COPPER TUBE
SPRING
CLAMP
INSERT HOSE OVER
COPPER TUBE AND
FASTEN WITH
SPRING CLAMP
Steam Lines and Condensate Return Instructions
The following instructions must be followed for installation of steam lines for the HM700. Failure to use recommended material
and exceeding maximum recommended length in Table 6, or failure to follow any other steam line installation instructions will
result in improper operation and could void the warranty.
Table 6. Recommended Steam Line Material for HM700 Duct.
* The use of steam line other than copper, stainless steel tube or Honeywell supplied steam line will void the warranty and may
adversely affect the operation of the humidifier.
* When using copper or stainless steel tubing (other than the supplied tubing), insulation is recommended due to high
temperature safety as well as reduced condensate.
To return condensate for HM700, insert copper tube (supplied with equipment) half way into the condensate opening of the fill cup
along with the spring clamp (supplied with equipment).
Insert the condensate hose into the condensate return hole at the top of the HM700, and over the copper tube. Fasten in place
with the spring clamp.
Fig. 11. Condensate return.
MAIN RULES FOR ATMOSPHERIC STEAM LINES
• Steam lines must not have any restrictions which could result in back pressure.
• Follow recommended materials, size and length, see tables.
• Install steam line in a vertical (upwards) fashion from the HM700 to the distribution nozzle. Consult Figures 12-14 for other
installation options.
• Insulate with 1.0 in. (2.5 cm) pipe insulation.
• Trap condensate (Use full size ‘T’ for Traps)
• Do not over tighten hose clamp at cylinder steam outlet. The maximum torque is 12 in-lbs.
• Support steam line so weight is not on cylinder.
• Condensate traps must be a minimum of 6 in. (15 cm) in height or duct static pressure +2 in. (5 cm), whichever is greater.
• Trapping by P-trap or pigtail. Support line as necessary to ensure it remains free of kinks.
Wiring to be performed by a licensed electrician. This unit must be installed on a GFI Circuit.
Equipment Damage Hazard
Failure to wire the humidifier in accordance with the wiring instructions could cause permanent damage.
Such errors will void the warranty.
HM700A Humidifier must be installed using a dedicated 15 amp circuit breaker and hardwired directly to comply
with UL product listing. All wiring must be done per governing electrical codes.
Electrical line cord plugs can overheat and result in risk of damage to property and/or personal injury. Note: Product
warranty will be voided if these instructions are not followed.
JUMPER WIRE INSTALLATION
• DO NOT install mains voltage wire (hot or neutral) into 120 or 240 terminal.
• DO install mains wires into L1 terminal (hot) and P terminal (hot/neutral).
• DO install jumper from P to 120 or 240 terminal (according to mains voltage).
Installation Steps
1. Unit requires a dedicated circuit with GFI protection. Bring circuit to a disconnect near the device to protect from electrical
shock when servicing.
2. Hard wire humidifier to disconnect according as shown at right.
3. Install factory-supplied jumper between the P terminal and the terminal that corresponds to supply voltage.
4. Remove green wire attached to case body and drain valve (remove canister for access).
5. Clip ground wire as close to drain valve as possible and remove excess.
33-00118EFS—0110
HM700A1000
HOT
HOT
GROUND
P
240
120
L1
GROUND
E
X
T
I
N
T
240 VAC (1 PHASE)
120 VAC (1 PHASE)
NEUTRAL
HOT
GROUND
P
240
120
L1
GROUND
NOTE: CONNECT 120 VAC,
“HOT”, TO L1
(OPTIONAL)
(OPTIONAL)
NOTE: POWER WIRES
CAN ALSO BE ROUTED
THROUGH OPENING IN
BACK OF CABINET
M35806
Fig. 16. Primary power connection.
NOTES:
—Honeywell requires the use of a GFI circuit on this device to protect the homeowner from electrical shock.
—When installed correctly, the green wire should be removed from the drain valve. The green wire comes pre-installed
from the factory to protect the homeowner in case of an improper installation or when it is not possible to retrofit a GFI
circuit. See Fig. 24 for the location of green wire on the drain valve.
—Ensure that adequate power is available to carry full humidifier amp draw as indicated on the specification label.
—Do not use neutral wire as a ground; connect a dedicated ground to ground termination.
—All wiring to be in accordance with national and local electrical codes.
1133-00118EFS—01
HM700A1000
HVAC
THERMOSTAT
R
C
U
U
S
S
GYWRRc
GYWR C
R/HUM
HUM
C
N/A
AP
G
F
R
F
N/A
M35754
OUTDOOR
SENSOR
AIR PROVING
OR JUMPER
EXTERNAL CONTROLS
Fan Interlock Wiring with HumidiPRO
When distributing steam into a duct, there could be a call for
humidity when there is no air flow. The HM700 with
HumidiPRO control or some other thermostat (such as the
Honeywell Prestige of VisionPRO
fan on a call for humidity. If using another thermostat, consult
that control’s manual for wiring instructions to enable the fan
with a powered humidification device.
NOTE: Humidifier will not start producing steam until
fan security loop is closed.
®
) can be used to enable a
This information is relevant to all controls, factory supplied or
otherwise. For wiring use minimum 18 AWG solid wire and
keep as short as possible.
Humidity Control
• Can be located either in return air duct (preferred) or in
room being humidified.
• Avoid placing near discharge diffuser of humidified air.
• Mount in area representative of room humidity (drafts,
doorways, sunlight, or an overhang such as a shelf can
affect reading).
Optional Outdoor Temperature Sensor (not shown; included
with HumidPRO)
• Mount outside in area representing air temperature.
HVAC
R
C
U
U
GYWR C
S
S
SPDT RELAY
COM
OUTDOOR
SENSOR
NC
NO
AIR PROVING
OR JUMPER
R/HUM
HUM
C
N/A
AP
G
F
R
F
N/A
NOTE:
SPDT RELAY IS NECESSARY TO PREVENT
ENERGIZING THE Y TERMINAL IF THE
GYWRRc
THERMOSTAT DOES NOT ISOLATE Y AND G.
Fig. 17. Wiring the steam humidifier with a digital thermostat.
THERMOSTAT
Fig. 18. Wiring the steam humidifier with a mechanical
M35730
thermostat.
NOTE: If a Prestige, VisionPRO, Lyric (or similar) are used to control humidity, wire the two HUM contacts to terminals 1 and 2
33-00118EFS—0112
on the HM700. With the jumper in place between terminals 1 and 8 on the HM700, only these two wires are necessary
to control humidity. Be sure to configure the control to force fan on with a call for humidity, or run on a heat cycle if the fan
enable wiring is not used.
START UP
CAUTION
FUSED DISCONNECT
CORRECT VOLTAGE / AMPS /
PHASE PER SPEC LABEL
(OPTIONAL)
MOUNTING
- UNIT LEVEL
- SCREWS INTO
STRUCTURAL
MEMBER
STEAM LINE
- ADEQUATE SLOPE
- NO RESTRICTIONS
- NO KINKS IN HOSE
- CONDENSATE TRAPS
ON LONG RUNS
HUMIDITY CONTROL
IN RETURN DUCT OR
LOCATION WHICH
REPRESENTS HUMIDIFIED
SPACE (NO DRAFTS, NOT
BY DOOR, NOT BY DIFFUSER)
1/2 IN. LINE (MINIMUM) TO WITHIN 4 FT (1.2 M). 30-100 PSIG
SPEC LABEL
AIR GAP
P TRAP
WITH 12 IN (30 CM)
MINIMUM DROP
BEND, OR OTHER
OBSTRUCTION
NOTE: U OR HUM TERMINALS IN SERIES BETWEEN TERMINALS 1 AND 2
AIR PROVING
(OPTIONAL)
IN SERIES BETWEEN
TERMINALS 1 AND 2.
JUMPER BETWEEN
TERMINALS 1 AND 8
MUST BE REMOVED.
2X DUCT HEIGHT
FROM FAN OR
TRANSITION
10 FEET (3 M) MINIMUM
4 FEET (1219) MINIMUM
2/3 DUCT
HEIGHT
8
(20 CM)
MINIMUM
HIGH LIMIT
ON/OFF
(OPTIONAL)
IN SERIES BETWEEN
TERMINALS 1 AND 2.
JUMPER BETWEEN TERMINALS
1 AND 8 MUST BE REMOVED.
M35807
DRAIN LINE SHOULD BE ROUTED TO ALLOW FREE FLOW OF
WATER. ENSURE ADEQUATE SLOPE, NO TRAPS, AND NO KINKS.
Installation Check
Before turning on power to the HM700, inspect the installation to ensure that it was carried out correctly.
HM700A1000
Fig. 19. Installation check.
Equipment Damage Hazard
Do not leave the On/Off/Drain switch in the drain
position for more than one complete drain cycle. The
drain valve solenoid may heat up and result in damage
to the valve and its wiring.
Do not attempt to drain with no water in system.
On/Off
The HM700 is factory-configured to operate as an On/Off
humidifier. It will run when 24 VAC from terminal 1 is fed back
into terminal 2 through an On/Off humidistat and other
security devices in series.
1333-00118EFS—01
HM700A1000
WARNING
Start Up Procedure
1. Examine the humidifier and installation for damage
and/or improper installation.
2. Ensure the cylinder is properly seated in the drain valve
and that the electrode plugs are pushed all the way
down on the cylinder pins.
3. Ensure that the front cover is in place and secured with
its retaining screws.
4. Open the supply water shut off valve.
5. Turn on the main power using the installed disconnect.
Personal Injury Hazard.
Damaged or improperly installed units must not be
operated. Damaged or improperly installed units may
present a danger to persons and property.
6. Turn the On/Off switch on the front of the humidifier to
On.
• The humidifier will perform a self-diagnostic
sequence during which the LED’s and internal
components will be momentarily activated. See
“LED Status Lights” on page 15 for an explanation
of the LEDs and sequences.
• If an error is detected during the self-diagnostic
sequence the humidifier will not start. The yellow
status LED will flash in sequence to indicate the
detected fault. See Tables 7 and 8 for information
on diagnosing and correcting faults.
• After the system test the humidifier is in normal
operation mode.
7. Check and adjust the control setpoint on the control and
high limit humidistat.
8. When the external humidistat generates a demand for
humidity and the security loop is closed the green
humidifying LED on the front of the humidifier will light
up, the power relay on the control board will engage, the
fill valve will activate (after a delay) and the cylinder will
slowly fill with water.
NOTE: While the cylinder is filling with water there
should be no water flowing down the drain. If
water is flowing down the drain it can indicate
excessive backpressure or a leaking drain valve.
See Troubleshooting.
9. If a fan enable relay is used, the green LED will continue
to flash until the air proving closes. Once the air closes,
the flashing green LED will become solid and the
humidifier will start steam production as described in
step 8.
10. It can take 5 – 10 minutes for the water to be heated up
by the submerged electrodes and for steam to be produced.
NOTE: If operated on low conductivity water it may take
several hours for the HM700 to reach full output
capacity. This is normal. During this time the
humidifier will not perform any drains and the
conductivity of the water in the cylinder will
increase. To expedite this process, add a
1/4 teaspoon of salt to the cylinder. This will
immediately increase water conductivity and
initiate heating.
33-00118EFS—0114
OPERATION
M35828
STATUS
DRAIN OFF ON
YELLOWGREEN
HM700A1000
LED Status Lights
The HM700 user interface includes 2 LEDs that provide
information about the humidifier status.
Fig. 20. LED status indicator lights.
Yellow and Green LED Flashing
Indicates there is no request for humidity.
Yellow LED Flashing
Fault detected, humidifier has stopped operating. Count
the number of flashes and see Table 8 for info.
Green LED Flashing
Indicates the humidifier is powered, but there is not a
request for humidity. Security loop (1-2) is open.
Yellow LED On
Indicates that water level is high.
When the yellow LED is steady on (not flashing) it indicates that the high water sensor has interrupted filling of
the cylinder. The LED is on for information only and
unless it persists for an extended period of time, it does
not require any action.
Green LED On
Indicates steam is being produced.
Selecting a Relative Humidity
Setpoint
The optimum humidity setpoint depends on the reasons that a
space is being humidified. The “ASHRAE Handbook HVAC
Applications” recommends specific design relative humidity for
specific applications.
Health and Comfort – The benefit of humidity is most
pronounced for health and comfort in the 40-60% range. A
humidity setting of 45-50% is recommended for this purpose
to prevent over humidifying.
Temperature Setback – In cold climates it is often necessary
to reduce the humidity level in a conditioned environment to
prevent build-up of condensation on the inside of exterior
walls, windows, and trim. It is highly recommended that the
humidity setback function of the HumidiPRO control be used
under these conditions to prevent damage from condensation.
The digital control with an outdoor temperature sensor
installed will automatically setback the humidity setpoint to
correspond with outdoor temperature.
1533-00118EFS—01
HM700A1000
STEAM
OUTLET
CONDENSATE
RETURN
FILL CUP
DRAIN VALVEDRAIN CANAL
FILL VALVE
CYLINDER
CYLINDER
PLUG
HIGH WATER
SENSOR PLUG
ON/OFF/DRAIN
SWITCH
CONTROL
BOARD
POWER RELAY
HIGH VOLTAGE
TE RM IN A L
BLOCK
TRANSFORME R
CONTROL
TE RM IN A L
STRIP
M35827
Fig. 21. Humidifier components.
ComponentFunction
Condensate ReturnProvides a connection to return condensate to humidifier.
Control Terminal StripTerminal strip for connecting external controls to humidifier and interfacing with other equipment.
Cylinder PlugPower connectors to electrodes in cylinder.
CylinderHolds electrodes in water. Current between electrodes generates heat used to generate steam.
Drain CanalCombines cylinder drain water and fill cup overflow into a single drain outlet.
Drain ValveDrains water from humidifier.
Control BoardControls all functions of the humidifier operation and provides input and output connections to
humidifier components.
Fill CupProvides an air gap for backflow prevention.
Fill ValveControls flow of water into humidifier.
High Voltage Terminal
Block
High Water sensor Plug Used to detect max water level in cylinder.
Primary power connection from remote disconnect to humidifier.
On/Off/Drain SwitchTurns power on/off to humidifier controller and drains the cylinder for servicing. Note: Turn off
humidifier disconnect to shut off primary power to the humidifier.
Power RelayTurns on/off power to cylinder electrodes based on a signal from the humidifier’s controller (mounted
on control board).
Steam OutletConnect to steam line with steam hose.
TransformerSteps primary voltage down to 24 VAC for the controller and internal components such as the fill valve
and drain valve.
33-00118EFS—0116
MAINTENANCE AND SERVICING
CAUTION
M35704
ELECTRODE INTERNAL
MOUNTING POINT.
HIGH WATER SENSOR PIN HAS
A PLASTIC COLLAR AROUND IT.
CONNECT ORANGE HIGH WATER
SENSOR WIRE HERE.
STEAM OUTLET
SECURE STEAM HOSE TO
OUTLET WITH HOSE CLAMP.
ELECTRODE PIN
CONNECT COLOR CODED CYLINDER
PLUGS TO PIN WITH CORRESPONDING
COLOR LABEL. THE SPRING LOADED
PLUG SHOULD FIT SNUGLY ON THE PIN.
REPLACE IF LOOSE OR ANY SIGNS OF
DAMAGE.
LABEL
IDENTIFIES CYLINDER INFORMATION.
ALSO INCLUDES SAFETY INFORMATION
AND CONTACTS.
Required Maintenance
The HM700 humidifier has been designed to require very little
maintenance. Regular maintenance consists of checking the
humidifier to ensure it is in good condition, replacing the
cylinder when the software advises that the cylinder is spent
and cleaning out the drain valve whenever the cylinder is
replaced.
CYLINDER SPENT FAULT
When the cylinder is spent the HM700 will stop operating and
the yellow LED will flash in a repeating pattern of 4 flashes.
SeeTable 8 on page 22 for more information on other flash
sequences. At this time the cylinder must be replaced.
The steam cylinder is disposable and must be replaced at end
of cylinder life. Cylinder life is dependent on water supply
conditions and humidifier usage.
HM700A1000
Failure to replace the cylinder at the end of
cylinder life will result in improper operation and
may result in damage to the humidifier. Honeywell
is not responsible for any damages resulting from,
or attributed to, the failure to replace a spent
cylinder (see Manufacturer’s Warranty).
NOTE: Honeywell recommends keeping a replacement
cylinder in stock throughout the humidification
season. This will prevent possible downtime
when the humidifier reports cylinder end of life.
REPLACEMENT CYLINDER
The label on the existing cylinder identifies the cylinder type in
its top left corner. When ordering a cylinder always quote the
three or five digit model number on the label, the humidifier’s
serial number and the humidifiers voltage. Serial number and
voltage are located on the specification label on the left side of
the humidifier.
Fig. 22. HM700 cylinder (HM700ACYL2).
1733-00118EFS—01
HM700A1000
WARNING
HOSE CLAMP
CYLINDER PLUG
LIFT VERTICALLY
ON/OFF/DRAIN SWITCH
CYLINDER
COVER SCREWS
TILT CYLINDER
FORWARD TO CLEAR
HOSE AND THEN
LIFT FROM DRAIN
VALVE.
TILT COVER
FORWARD TO
REMOVE.
M35705
Removing the Cylinder
Disconnect main power at the external disconnect
before any servicing.
The inside of the humidifier cabinet contains high
voltage components and wiring. Access should be
limited to authorized personnel.
1. Drain the existing cylinder by switching the On/Off/Drain
switch to the Drain position. Let the humidifier drain until
no more water is flowing out to drain (usually not more
than 10 minutes).
2. Turn the humidifier On/Off/Drain switch to off.
3. Close supply water shut off valve.
4. Turn off power to the humidifier with the external discon-
nect.
5. Remove the two screws securing the front cover.
6. Remove the cylinder plugs from the cylinder pins by
pulling vertically.
7. Using a flat screwdriver loosen the hose clamp where
the hose is connected to the cylinder.
8. Tip the top of the cylinder forward to pivot it out of the
steam hose. When free of steam hose lift the cylinder
out.
NOTE: The HM700 has a re-usable tie strap to secure the
cylinder for transit as well as home installation.
This must be removed or loosened to remove the
cylinder. Secure when new cylinder is installed.
33-00118EFS—0118
Fig. 23. Cylinder removal.
HM700A1000
CAUTION
CYLINDER PORT
AND O-RING
GROUND
WIRE
SOLENOID
SPADE
CONNECTORS
BRASS NUT
(ACTUATOR)
SCREWS
HOSE AND
HOSE CLAMP
M35700
M35707
SLEEVE AND
SOLENOID
SPRING
(NOTE ORIENTATION)
PLUNGER
ACTUATOR
Drain Valve Cleaning
Always clean the drain valve before installing a new cylinder.
Scale from the spent cylinder may have fallen into the drain
valve and could prevent its proper operation. To properly clean
the drain valve it must be removed and disassembled.
1. Disconnect spade terminals from the drain valve.
2. Remove the two screws holding the valve to the drain
pan.
3. Squeeze the tabs of the spring clamp holding the hose
to the drain valve and slide it up the hose. Pull hose
from drain valve. Lift the drain valve from the drain pan.
4. Unsnap red coil cap on solenoid and remove the sole-
noid from the valve.
5. Loosen brass nut holding actuator to plastic housing
with a wrench and disassemble actuator.
6. Clean actuator components and valve housing (inlet
port, outlet port, and cylinder port). Put new o-ring that
was supplied with new cylinder into valve.
7. Reassemble actuator making sure tapered end of
spring is oriented as shown in Fig. 25. Tighten brass nut
1/4 turn past hand tight.
8. Clean out end of hose and reattach to valve. Slide hose
clamp back in place and place valve into drain pan.
9. Secure valve with 2 screws to drain pan.
Installing the New Cylinder
Make sure the new cylinder is a HM700ACYL2. Use
of any other model or remanufactured cylinders
will void the HM700 warranty.
1. Insert cylinder into drain valve. Tilt cylinder forward and
fit end of steam hose to steam outlet. Tip cylinder back
into place.
2. Tighten hose clamp being careful not to over tighten and
crush the plastic cylinder steam outlet.
3. Attach color-coded cylinder plugs to the corresponding
color-coded cylinder pin. Push down completely.
Connect high water sensor plug. Spring-loaded plugs
should fit snuggly onto the cylinder pin. Replace if they
are loose or damaged.
4. Re-fasten tie strap.
5. Replace the humidifier cover and secure with two
screws.
6. Turn on power to humidifier with the external
disconnect.
7. Open supply water shut off valve.
8. Turn the humidifier On/Off /Drain switch to On.
Extended Shutdown
Should it be required to disconnect power to the humidifier for
a period of extended shut-down, always drain the cylinder first.
Fig. 24. Drain valve.
1. Switch the On/Off/Drain Switch to the Drain position.
2. Wait until the humidifier is completely drained (usually
takes less than 10 minutes).
3. Turn the On/Off /Drain switch to the off position.
4. Shut off power to the humidifier with the external
disconnect.
5. Close the supply water shut-off valve.
NOTE: As long as the HM700 is powered, it will
automatically drain the cylinder when there has
not been a call for humidity for an extended
period of time. This feature will reduce or prevent
the possibility of corrosion of the electrodes and
the accumulation of algae and bacteria growing
in the cylinder. The cylinder will remain empty
until there is a call for humidity at which time the
fill valve will open and refill the cylinder. The unit
will go through its normal process for optimum
operation.
STARTING AFTER EXTENDED SHUTDOWN
1. Check to see the humidifier has not been damaged and
the installation has not been altered. See “Start Up
Procedure” on page 14.
2. Turn on the power to the humidifier with the external
disconnect.
3. Turn the On/Off/ Drain switch to the Drain position.
4. Wait until there is no water flowing to drain. It usually
takes less than 10 minutes.
5. Follow the start up procedure on page 14.
Fig. 25. Drain valve actuator assembly.
1933-00118EFS—01
HM700A1000
CAUTION
CAUTION
TROUBLESHOOTING
High Voltage Hazard.
Be aware, when troubleshooting, that the humidifier is
powered by high voltage and familiarity with both good
practices and wiring of the humidifier is recommended.
Any troubleshooting that requires opening the cabinet
should be done by qualified personnel.
Burn and Scalding Hazard.
Hot water or steam with a temperature above 120 °F
(49 °C) can cause burns from scalding.
NOTE: Most humidifier faults are not caused by faulty
equipment but rather by improper installation. A
complete fault diagnosis always involves a
thorough examination of the entire system.
Often, the steam hose connection has not been
properly executed, or the fault lies with the
humidity control system.
TROUBLESHOOTING REQUIREMENTS
• Ensure the installation meets the installation requirements
outlined in the Installation Chapter of this manual.
• Familiarize yourself with the operation of the humidifier by
reading the Operation Chapter of this manual.
• Wiring diagram for specific for your humidifier is installed
on the inside of the humidifier door. A generic copy of the
HM700 wiring diagram is also included at the end of this
chapter for reference purposes.
• When contacting your local representative or Honeywell for
troubleshooting assistance, please ensure the serial
number has been obtained for reference purposes.
The following section provides general guidelines for
troubleshooting the HM700 humidifier and auxiliary
components. For detailed troubleshooting information refer to
the manuals that were provided with the auxiliary equipment
and toTable 8, “Troubleshooting HM700 Faults,” on page 22.
SymptomCauseCorrective Action(s)
Nothing happens when On/Off
switch is turned on.
Humidifier will not humidify or not
reaching HM700 setpoint
Humidifier has faulted and yellow
LED is flashing
Table 7. General troubleshooting.
Fuse blownCheck inline fuse between transformer and
control board.
Incorrect VoltageCheck voltage against spec label and correct.
Step Down Transformer not outputting
24VAC
Incorrect primary power jumperCheck that jumper on high voltage terminal block
Safety loop openCheck if there is 24 VAC at terminal 2.
No demand signalCheck voltage between terminal 3 and 4. For
Capacity has been manually limitedCheck Manual Capacity adjustment
Low conductivity waterCheck if yellow LED is on. If operated on low
No airflow in ductCheck that humidifier fan enable (terminals 19-20)
Software has detected an abnormal
condition
Replace the transformer.
is connected between P and terminal
corresponding to supply voltage. See Fig. 16.
Check wiring and operation of On/Off devices
connected to terminal 1 and 2.
Check jumper is installed in air proving safety
loop, terminal 1 and 8.
demand configuration 35% of full-scale signal
must be present for humidifier to start.
potentiometer. Clockwise increases capacity.
conductivity water it may take several hours for
the HM700 to reach full output capacity. This is
normal. During this time the humidifier will not
perform any drains and the conductivity of the
water in the cylinder will increase. Conductivity
can be increased more quickly by adding
1/4 teaspoon of salt.
are properly wired to furnace. Check air proving
wired to terminal 8.
Refer to Table 8 on page 22.
33-00118EFS—0120
HM700A1000
Table 7. General troubleshooting. (Continued)
SymptomCauseCorrective Action(s)
Distributor spitting out waterDistributor not levelUse support at end of distributor to ensure it is
level.
“P” Trap too close to distributor“P” Trap must be a minimum of 12 in (30 cm)
below the distributor to ensure flow. Relocate if
required.
Condensate line not sloped sufficiently Sufficient slope to ensure flow is required.
Reinstall if required.
Trap blockedCheck that water flows through trap. Clear out if
blocked.
Steam line not insulatedIf steam line is long, condensate build up could
overload distributor condensate port. Insulate line
to improve efficiency and install additional
condensate traps as required.
Incorrect steam line installationCheck that steam line has been installed with
condensate traps and slope. See “Steam Lines
and Condensate Return Instructions” on page 8.
Condensation in ductInstallation clearances not observedRefer to distributor installation manual for required
clearances. Relocate distributor if required.
Design conditions changedCheck supply air temperature and humidity to
determine if conditions have changed.
High limit not functioningCheck setting and operation of high limit. Replace
if defective.
Humidifier is tripping the GFI.Humidifier is wired to a GFI circuit.
Drain valve ground wire is not
disconnected.
Review the Electrical Installation Steps and Notes
on page 10 for GFI guidelines and ground wire
removal information.
2133-00118EFS—01
HM700A1000
HM700 Faults
The self-diagnostic system built into the HM700 is continually
monitoring the operation of the humidifier. When an abnormal
condition occurs that cannot be self-corrected by the software
the HM700 will turn off power to the cylinder, drain the
cylinder, and annunciate the fault using the yellow status LED.
LED Flash Sequence
To differentiate between different fault conditions the yellow
LED is flashed in different sequences. Table 8 lists the fault
sequences that can be displayed, their meaning, possible
cause and suggested corrective actions.
Clearing a Fault
• Check the flash sequence against the list of fault messages
and take any necessary actions to correct the cause(s) as
outlined in Table 8 on page 22.
• Power cycle the humidifier with the On/Off switch waiting
10 seconds between turning it off and on.
Table 8. Troubleshooting HM700 Faults.
Yellow
LEDSymptomCauseCorrective Action(s)
1 flashExcess Current
Current has
exceeded 130% of
max
2 flashes No Current
Fill valve activated
for long time but
high water level not
reached.
Fill should be faster
than 1” per minute.
3 flashes No Current, High
Water
Water level at top of
cylinder with no
current
4 flashes Cylinder Spent
Electrodes covered
with scale.
Drain blocked water over concentrated Clean the drain line
Drain solenoid not energized, water
over concentrated
Filling too fast, fill valve damaged and
leaking
Filling too fast, wrong fill valveFill valve may be defective - replace if necessary
Water supply too conductivea) Change the water supply
Humidifier short cyclinga) Check if high limit or other On/Off control is cycling
Wrong cylinder installedInstall correct cylinder model
Cylinder Spent but not detected by
software
Condensate from other sourceRemove condensate returns other than from steam line.
Back pressureEliminate back pressure
Drain valve leaking or stuck openClean drain valve or replace (see maintenance chapter)
Water shut off valve closedOpen shut off valve
Fill Valve strainer blockedClean out strainer on fill valve inlet.
High system back pressurea) Check for kinked hose
High water sensor not connectedCheck that cylinder plug with white marker is connected
Low water conductivitya) Check if potable water supplied to unit, not treated
Primary wire not looped through
current transformer.
High water sensor plug is on an
electrode pin.
Cylinder plugs installed incorrectlyCheck that cylinder plugs colors match markers next to
Cylinder electrodes are covered with
scale and humidifier cannot meet
demand
Check and correct wiring to drain valve.
Replace the fill valve
b) Contact Honeywell representative for recommendation
On/Off in less than 5 minutes. Check location and setting
of high limit.
b) Reduce the output by turning down the potentiometer
Replace the cylinder (see maintenance chapter)
b) Check for proper condensate removal (see
installation)
to short electrode with a plastic well around it and to
control board.
water (RO or DI).
b) Check conductivity of water. If less than 150 μS, add
1/4 teaspoon of salt to fill cup and restart unit.
Rewire primary wire through current transformer.
Install high water senor plug on cylinder pin with shroud
around it.
electrodes on cylinder and that white marked cylinder
plug is connected to short electrode located in plastic
well.
Replace cylinder with same model number (see
maintenance chapter).
33-00118EFS—0122
POTENTIOMETER
P8
HIGH WATER
K2
K3
P1 P2 P3 P4 P5 P6 P7
240/208/
120 VAC
24 VAC
1.5 AMPS
CYLINDER
FILL V
DRAIN V
1
2
3
4
8
19
20
21
R / HUM
AP
GF
RF
C
HUM
N/A
N/A
120L1
EXTERNAL
INTERNAL
240 P
ON/OFF/
DRAIN
SWITCH
TRANSFORMER
N/A
120L1
240 P
S
STATUS
LAMPS
G
Y
NOTE: INSTALL JUMPER FROM PTO TERMINAL
CORRESPONDING TO MAINS VOLTAGE.
HOT
NEUTRAL
GROUND
HOT
HOT
GROUND
240 VAC
120 VAC
NOTE:
DRY POINTS FOR FURNACE
FAN ENABLE.
24 V PILOT CONTROL ONLY
N/A
FACTORY INSTALLED TERMINAL
HUMIDITY
CONTROL
24V
HUM
CALL
M35721
HM700A1000
Fig. 26. Wiring diagram.
2333-00118EFS—01
HM700A1000
5 YEAR WARRANTY
Honeywell warrants this product to be free from defects in the workmanship or materials, under normal use and service, for a
period of five (5) years from the date of purchase by the consumer. If at any time during the warranty period the product is
determined to be defective or malfunctions, Honeywell shall repair or replace it (at Honeywell's option).
If the product is defective,
(i) return it, with a bill of sale or other dated proof of purchase, to the place from which you purchased it; or
(ii) call Honeywell Customer Care at 1-800-468-1502. Customer Care will make the determination whether the product should be
returned to the following address:
Honeywell Return Goods, Dock 4 MN10-3860, 1985 Douglas Dr. N., Golden Valley, MN 55422,
or whether a replacement product can be sent to you.
This warranty does not cover removal or reinstallation costs. This warranty shall not apply if it is shown by Honeywell that the
defect was caused by damage which occurred while the product was in the possession of a consumer.
Honeywell’s sole responsibility shall be to repair or replace the product within the terms stated above. HONEYWELL SHALL NOT
BE LIABLE FOR ANY LOSS OR DAMAGE OF ANY KIND, INCLUDING ANY INCIDENTAL OR CONSEQUENTIAL DAMAGES
RESULTING, DIRECTLY OR INDIRECTLY, FROM ANY BREACH OF ANY WARRANTY, EXPRESS OR IMPLIED, OR ANY
OTHER FAILURE OF THIS PRODUCT. Some states do not allow the exclusion or limitation of incidental or consequential
damages, so this limitation may not apply to you.
THIS WARRANTY IS THE ONLY EXPRESS WARRANTY HONEYWELL MAKES ON THIS PRODUCT. THE DURATION OF
ANY IMPLIED WARRANTIES, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE, IS HEREBY LIMITED TO THE FIVE-YEAR DURATION OF THIS WARRANTY.
Some states do not allow limitations on how long an implied warranty lasts, so the above limitation may not apply to you. This
warranty gives you specific legal rights, and you may have other rights which vary from state to state.
If you have any questions concerning this warranty, please write Honeywell Customer Care, 1985 Douglas Dr, Golden Valley, MN
55422 or call 1-800-468-1502.
IMPORTANT
To maintain warranty, only Honeywell approved parts and cylinders may be used in the operation of the product.
Automation and Control Solutions
Honeywell International Inc.
1985 Douglas Drive North
Golden Valley, MN 55422
customer.honeywell.com