Atwood AFMD16, AFMD20, AFMD25, AFMD30, AFMD35 Technical Installation Manual

Literature number 31971

hydro flame™

AFM Series Furnaces Models

AFMD16 AFMD20 AFMD25 AFMD30 AFMD35

Technical Installation Manual

1120 North Main Street • Elkhart, IN 46514 USA & Canada : 1-866-869-3118 Internet: http://www.atwoodmobile.com

WARNING

Installation of this appliance must be made in accordance with the written instructions provided in this manual. No agent, representative or employee of Atwood or other person has the authority to change, modify or waive and provision of the instructions contained in this manual.

WARNING

Avoid possible injury or death

Improper installation, adjustment, alteration, service or maintenance can cause property damage, personal injury or loss of life. Refer to the

installation instructions and/or owner’s manual provided with this

appliance. A qualified installer, service agency or the gas supplier must perform installation and service.

CRITICAL INSTALLATION WARNINGS

 DO NOT install furnace on material that restricts return air, like carpet

or any soft material such as vinyl.

 DO NOT install furnace where clearance to combustibles cannot be

maintained.

 DO NOT modify furnace in any way.  DO NOT alter furnace for a positive grounding system.  DO NOT hi pot furnace unless electronic ignition system (circuit

board) has been disconnected.

 DO NOT use battery charger to supply power to DC model furnace

even when testing.

 DO NOT use 120-volt AC current with DC models.  DO NOT use furnace cabinet area as a storage compartment.  DO NOT vent furnace with venting system serving another appliance.  DO NOT vent furnace to an outside enclosed porch area.  DO NOT use for temporary heating of buildings or structures under

construction.

 Protect building materials from degrading from flue gas exhaust.  Protect furnace electrical components from water.  Compartment must be closed when operating unit.  Should the gas supply fail to shut off or if overheating occurs, shut off

the gas valve to the furnace before shutting off the electrical supply.

 DO NOT use this furnace if any part has been under water.

CAUTION

PERSONAL INJURY

All sheet metal edges are sharp care should be taken when handling or brushing up against them.

FOR YOUR SAFETY

Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance.

WARNING

Be sure the furnace and all ignition systems are “off” during any type of

refueling and while vehicle is in motion or being towed.

TO THE INSTALLER: LEAVE THIS MANUAL WITH

THE APPLIANCE.

TO THE CONSUMER: RETAIN THIS MANUAL FOR

FUTURE REFERENCE.

SAFETY ALERT SYMBOLS

Safety Symbols alerting you to potential personal safety

hazards obey all safety messages following these symbols

WARNING

Avoid possible injury or

death

CAUTION

Avoid possible injury

and/or property damage

WARNING

FIRE OR EXPLOSION

If the information in this manual is not followed exactly, a fire or explosion may result causing property damage, personal injury or loss of life.

FOR YOUR SAFETY

WHAT TO DO IF YOU SMELL GAS:

 Extinguish any open flame.  Evacuate all persons from the vehicle.  Shut off the gas supply at the gas container or

source.

 Do not touch any electrical switch, or use any

phone or radio in the vehicle.

 Do not start the vehicle’s engine or electric

generator.

 Contact the nearest gas supplier or qualified

service technician for repairs.

 If you cannot reach a gas supplier or qualified

service technician, contact the nearest fire department.

 Do not turn on the gas supply until the gas

leak(s) has been repaired.

A qualified Service Technician

Service Center or gas supplier must perform

installation and service.

English, Français (et Canada)

This instruction manual is for use by an authorized service technician to install an Atwood – hydro flame™ furnace. Should you require further information, contact your dealer or Atwood Mobile Products LLC. This furnace design has been certified for installation in recreation vehicles as a MSP Category III furnace. Follow this installation instruction to insure safe operation of the furnace. Failure to install furnace according to this installation instruction nullifies the furnace warranty.

Effective 5/2014

WARNING

CARBON MONOXIDE POISONING

Properly seal vent assembly to prevent carbon monoxide from entering coach.

 DO NOT draw combustion air from living area.  DO NOT vent exhaust air into the living area or an enclosed porch.

WARNING

CARBON MONOXIDE POISONING

 Furnace must be installed and vented to these instructions.  Improper installation, adjustment, alteration, service or maintenance

can cause injury or property damage. Improper installation location may cause furnace to produce negative pressure, affecting combustion air or venting of other appliances.

WARNING

CARBON MONOXIDE POISONING

 Properly seal door to prevent carbon monoxide from entering coach.  Properly adjust draft cap to prevent carbon monoxide from entering

coach.

Model Nomenclature

AF M D

25 1 1 1 A

Atwood

Furnace

Cabinet

Size

Voltage

Input

Btu/hr

Gas

Type

Gas

Location

Valve

Model Rev

M=medium

D=12 VDC

12K 16K 20K 25K 30K 35K 40K

1=LP 1=door

2=LD (small

vent)

3=door w/

rear gas

fitting

4=door

w/connector

5=door w/

connector &

rear gas

fitting

Single

Models

AFMD16111

AFMD16121

AFMD20111

AFMD20121

AFMD25111

AFMD25121

AFMD30111

AFMD30121

AFMD35111

AFMD35121

Type of

Gas

LP/

Propane

LP/

Propane

LP/

Propane

LP/

Propane

LP/

Propane

BTU Input

16,000

20,000

25,000

30,000

34,000

BTU

Output

12,160

15,200

19,000

22,800

25,840

Duct Static

Pressure

.20” WC

.10” WC

Amperage

(AMPS)

4.2

7.5

11.1

Watts

132

Power

Supply

(Volt DC)

Return Air

80 in2

Minimum

Return Air

65 in2

Model

AFMD16

AFMD20

AFMD25

AFMD30

AFMD35

Bottom

+ 1 duct

4” Duct

2 min +1

3 min +1

Flex or Rear

3 min +1

Full Side

+1 duct

Approx.

Width

Height

Depth

Weight

Casing

16-1/2”

7”

20”

Furnace

26lbs.

Boxed

29 lbs.

STD Door

19-1/4”

9-3/4”

3/4”

FLUSH

DOOR

19-3/8”

10-1/4”

7/32”

Vent LD

4-3/4”

6-5/16”

1-1/16”

clearances

Top

Sides

Rear

Bottom (to

screw heads)

Blower (side

opening)

Vertical /

Horizontal

1/2”

0”

36 sq. in.

SPECIFICATIONS

MODELS Table 1

Contents

SPECIFICATIONS ..................................................................... 2

MODELS Table 1 ............................................................................. 2

DUCTING CONFIGURATIONS Table 2 ........................................... 2

DIMENSIONS Table 3 ...................................................................... 2

MINIMUM CLEARANCE TO COMBUSTIBLES: Table 4 ................. 2

INSTALLATION AND SAFETY CODES.................................... 3

GENERAL FURNACE LOCATION AND INSTALLATIONS ..... 3

FURNACE INSTALLATION ....................................................... 3

SIDEWALL CUTOUT ................................................................. 3

SMALL VENT INSTALLATION ........................................................ 4

STANDARD DOOR INSTALLATION ............................................... 4

FLUSH DOOR INSTALLATION ....................................................... 4

DUCTING OPTIONS .................................................................. 5

FLEXIBLE DUCTING SYSTEMS ...................................................... 5

HARD DUCT FLOOR SYSTEMS...................................................... 5

HORIZONTAL OR VERTICAL BOTTOM DISCHARGE ................... 5

FLEX ADAPTER PLATE .................................................................. 5

AIR FLOW CHECK .................................................................... 6

PROPANE GAS CONNECTION ................................................ 6

ELECTRICAL CONNECTIONS ................................................. 6

THERMOSTAT INSTALLATION ............................................... 6

OPERATING INSTRUCTIONS .................................................. 7

TO SHUT DOWN ....................................................................... 7

WIRING AND LADDER DIAGRAM ........................................... 8

PART DRAWINGS & PART LISTS ........................................... 9

* (WC = WATER COLUMN)

DUCTING CONFIGURATIONS Table 2

Notes: (two top ducts supplied are for use in addition of these installation and are not allowed to be used alone)

 Bottom Discharge: This installation is for horizontally installed

units and can be used only with the addition of one duct any location.

 4” Ducting: when using 4” ducting option one duct from each side

must be used. When using side ducts rear duct openings will give the best performance and should be used whenever possible front ducts are acceptable.

 Flex or Rear Discharge: This installation must use all three of the

rear ducts one more duct maybe added if required.

 Full Side: Full side discharge unit are for installation of the furnace

in a vertical mounting position and can be used with one additional duct any location.

DIMENSIONS Table 3

MINIMUM CLEARANCE TO COMBUSTIBLES: Table 4

Floorboards, walls & similar combustible building materials must be provided the full length and width of unit.

 Spacing of 1/4” to ducting within 3 feet of furnace must be provided

A B D

Side Wall Cutout Small Vent Max

Wall Thickness 2-1/2”

3-1/4” Dia.

Side Wall Cutout Standard Door

(horizontal or vertical)

17” MAX

7-1/2”

MAX

Side Wall Cutout Flush Door

(corner cut requires 3/4” radius)

(horizontal or vertical)

18-3/4”

MAX

9-3/8”

MAX

unless UL listed wire bound vinyl ducts are used. All ducting material used to be rated for continuous use at minimum of 200°F.

 Clearances are specifically for plywood or similar building materials

surrounding the furnace (i.e. Furnace should not be located under furniture or in a closet space where clothing or other material could be located).

 To install without adding the 36 sq. in. cutout on the blower side

supply the unit (blower side) with 2” clearance full length of the unit.

 Furnace efficiency rating is a thermal rating determined under

continuous operating conditions, independent of any installation. Efficiency rate is given at 76% minimum; actual efficiency rating may be higher.

 Return air is supplied through openings in furnace casing. All return

air passages must be kept clear for furnace to function properly. Refer to Minimum clearance to floorboards, walls & similar combustible building material.

 The total unobstructed return air opening size(s) must not be less

than specified in Table 1. Failure to meet minimum return air requirements nullifies furnace warranty.

INSTALLATION AND SAFETY CODES

USA and Canada – follow all applicable state and local codes – in the absence of local codes or regulations, refer to current standards of:

 Recreation Vehicles ANSI A119.2/NFPA 501C  National Fuel Gas Code ANSI Z223.1 and/or CAN/CGA B149

Installation Codes

 This furnace must be installed in accordance with the

manufacturer’s instructions and the manufactured Home

Construction and Safety Standard, Title 24 CFR, part 3280, or when such standard is not applicable, the Standard for Manufactured Home Installations. (Manufactured Home Sites, Communities and Set-Ups), ANSI A255.1 and/or CAN/CSA-Z240 MH Series M92 Canadian Standard for Mobile Homes.”

 ANSI A 255.1 and/or CAN/CSA-Z240.6.2 MH Series, Mobile Homes  Ground National Electrical Code ANSI/NFPA 70 and/or CSA C22.1,

Part 1

 Park Trailers ANSI 119.5

GENERAL FURNACE LOCATION AND INSTALLATIONS

 All models can be installed in either a horizontal or vertical mounting

position horizontal installed units have the gas line positioned on top or rear, vertical installed units have the vent located at floor level and gas line at right side and rear.

 Always install furnace through an exterior wall.  DO NOT install furnace near tilt-out rooms, slide-outs, doors or

other projection that could obstruct furnace exhaust.

 Locate furnace near midpoint of coach for single furnace

applications.

 Installation must provide accessibility if any repairs are necessary to

the furnace. Failure to meet this requirement will create additional labor costs that will be the responsibility of the installer.

 DO NOT install vent in areas where projection or door openings

come within 6” of vent opening.

 DO NOT install furnace in an area where wires, pipes or other

objects will interfere with installation or operation of furnace.

 DO NOT install furnace on material that restricts return air, such as

directly on carpet, or soft material (like vinyl). If you must install furnace on carpet or soft material, install furnace on cleats, or on a wood or metal panel extending the full width and depth of furnace plus minimum clearance to combustibles.

 DO NOT use petroleum or citrus type cleaner on plastic parts, as

damage may occur.

 CAUTION: Due to the differences in vinyl siding materials this

appliance should not be installed without first consulting with the manufacturer of siding.

 A gas-fired furnace for installation in a residential garage must be

installed so the burner(s) and the ignition source are located not less than 18 in (457mm) above the floor and the furnace must be located or protected to avoid physical damage by vehicles.

FURNACE INSTALLATION

 The furnace should always be installed level (front to back, side to

side) to prevent water intrusion into the interior.

 Set aside venting and outer door parts for installing on the outside

of coach.

 NOTE to assure sufficient return air to circulating blower maintain

specified clearances see table 4.

 If units are installed using the small outside vent system access to

the inside of the coach must be provided directly in front of the unit to remove for service suggested opening size 17” wide by 8-3/8” height.

 Remove knockouts from furnace and install duct adapters for side

discharge by inserting back flange over casing and inserting tab into square notch, then twist adapter 90°.

 Insert furnace into cabinet opening and secure with two screws

through casing legs to floor. Units are secured by means of door or vent systems through the coach sidewall with casing legs at the rear.

 Attach flexible ducting over duct adapters and secure. All flex

ducting requires rating of 200°F.

 Run ducting to locations keeping bends and excess ducting to a

minimum and secure to registers.

 Connect wiring to located on the top of the furnace. See wiring

connection section.

 Connect gas line to top or rear of furnace. See gas connection

section.

1. Cut the required exterior wall opening for your venting system see Figure 1.

2. Configure furnace for ducting option to be used refer to duct configurations table 2.

3. Install furnace into opening and attach ducting to adapters.

4. Make gas and electrical connections, which are located on the top of the unit.

5. See door or vent installation instruction below on how to complete the venting system.

SIDEWALL CUTOUT

* Recommended exterior wall thickness 0” to 2-1/2”.

* Small vent system 0” to 2-1/4”.

WALL CUTOUTS Table

Figure 1

DO NOT oversize hole – over sizing can result in water leakage. Zero clearance around air intake cutout for best sealing condition.

SMALL VENT INSTALLATION

Figure 2

 To prevent moisture from entering inside of coach, apply RTV type

sealant to the back of the bezel flange of the vent part.

 Vents are designed to allow water drainage when installed correctly.  Vents are design to allow for different wall thickness up to a

maximum of 2-1/2”

1. Locate vent hole cutout as called out in Figure 2.

2. Drill 3-1/2” diameter hole through sidewall of coach maximum wall thickness 2-1/2”.

3. Remove vent and vent ring from furnace.

4. Insert furnace from backside of wall, lining up hole in wall with vent in furnace.

5. Apply sealant to back of vent ring.

6. Install vent assembly with HOT at top on horizontal installations and HOT on right side for vertical installations. Vent ring must slip inside combustion air intake tube. Secure to wall with 2 screws not provided.

7. Vent assembly must maintain minimum overlap of 1-1/4” on exhaust

tube and 1/2” minimum on combustion air tube. DO NOT exceed

maximum wall thickness.

8. Secure furnace to floor with legs provided on back of casing. For vertical units casing legs can be positioned for placement to secure furnace.

STANDARD DOOR INSTALLATION

Figure 3

 The furnace must always be installed level (front to back, side to

side) to prevent water intrusion into the interior.

 To prevent moisture from entering inside of coach, apply RTV type

sealant to all sealing areas.

 The door bezel must fit tightly, to prevent water leakage.  Doors are designed to allow water drainage in either horizontal or

vertical installations. Proper location of vent assembly is important for proper exhausting of fumes and proper function of furnace.

1. Locate and cut hole location in side wall per figure 3.

2. Apply RTV type sealant to entire back flange of bezel creating a sealing area.

3. Pull furnace forward through cutout about a 1” inch, slip bezel around casing, and flush inner flange with casing.

4. Secure bezel to furnace casing with 6 screws.

5. Push furnace and bezel back tight against side wall and secure with 14 screws.

6. When installing screws DO NOT deform bezel.

7. Connect the gas line to the valve and push the gas line plug into casing opening.

8. Remove excess sealant from around bezel and visually inspect bezel to make sure it is completely sealed.

9. Secure furnace to floor with mounting legs provided.

10. Fasten door and vent with 6 screws provided.

FLUSH DOOR INSTALLATION

Figure 4

 The furnace must always be installed level (front to back, side to

side) to prevent water intrusion into the interior.

 To prevent moisture from entering inside of coach, apply RTV type

sealant to all sealing areas.

 The door bezel must fit tightly, to prevent water leakage.  Doors are designed to allow water drainage in either horizontal or

vertical installations. Proper location of vent assembly is important for proper exhausting of fumes and proper function of furnace.

1. Locate and cut hole location in side wall per figure 4.

2. Flush mounted doors system require that the furnace be install on a

1” high platform to allow for the door cutout to be level with the floor

surface.

3. Apply RTV type sealant to entire back flange of bezel creating a seal area.

4. Secure bezel by inserting bezel into wall cutout and securing through the 10 mounting tabs to the side wall framing. Make sure that the bezel is tight against the side wall.

5. Connect the gas line to the valve and push the gas line plug into casing opening.

6. The door bezel must fit tightly against sidewall to prevent water leakage.

7. Remove excess sealant from around bezel and visually inspect bezel to make sure it is completely sealed.

8. Secure furnace with mounting legs provided.

9. Fasten door and vent with 6 screws provided.

DUCTING OPTIONS

Models

Required Discharge Area

AFM (16)(20)

24 in2

AFM (25)(30)

36 in2

AFM (35)

36 in2

Models using bottom discharge options

48 in2

Models using vertical discharge options

48 in2

REQUIRED MINIMUM DISCHARGE

 Proper duct installation is critical to operation of furnace. When

installing ducts, use materials rated for continuous use at 200°F.

 See minimum clearance to floorboards, walls & similar combustible

building materials.

 Each 4-inch duct opening provides 12 in2 of discharge area. Provide

an extra 12 in2 of non-closeable duct discharge area for each closeable register used.

 Use of 2” ducting does not count toward achieving minimum

discharge requirements. Ducting into dead air space with no return air, such as holding tank areas, does not count toward achieving minimum discharge requirements.

 Adjust ducting installation to obtain air rise of 100°F-130°F.  Horizontally installed furnaces – using side duct options – must

have a minimum of one duct from both left and right side of casing.

FLEXIBLE DUCTING SYSTEMS

When designing flexible duct systems:

 Avoid sharp bends or crushed ducts.  Stretch all ducts and run them directly to outlets, keeping quantity

and angles of bends to a minimum.

1. Remove knockout plates from desired outlets.

2. Attach a duct adapter to each opening by inserting flange over casing, locking the tab into casing slot and turning adapter 90°.

3. Attach and secure four-inch flexible ducts to adapters.

4. Run ducts to desired location within RV, secure to registers.

5. Additional ducting may be needed to maintain correct static pressure.

 When hard ducting is 1-1/2” in depth, an additional flex duct may be

needed to maintain installation duct air flow requirements.

 DO NOT install floor registers within 2 feet of return air openings.

See ducting option from casing top and bottom areas. These options can be with flex ducting or by hard ducting installations. Hard ducting must be sealed to insure proper operation of the appliance.

HORIZONTAL OR VERTICAL BOTTOM DISCHARGE

Figure 6

 Units can be installed as bottom or vertical bottom discharge

systems. See figure 6 for cutout location and sizes.

1. Remove bottom discharge knockout or side cover plate, these ducting options must be connected to a ducting system.

2. Insure sealing of all joints when use of a gasket and plenum plate for hard ducting configurations.

3. Other methods of sealing furnace to the floor are acceptable as long as clearances and seals meet requirements of clearances and temperature.

4. Fasten plenum plate over floor cutout. If a gasket and plenum plate is not used seal furnace to hard duct system making sure seal is airtight.

5. Position gasket on plenum over hole opening see Figure 6.

6. Set furnace on gasket; make sure gasket remains in position.

7. Additional ducting can be used to maintain correct air flow and temperature rise.

FLEX ADAPTER PLATE

Figure 5

HARD DUCT FLOOR SYSTEMS

When designing hard ducting systems:

 Undersized ducting will cause high temperature limiting.  Oversized ducting will cause inadequate air flow from registers.

Figure 7

 A flex adapter may be used to provide more flexibility for alignment

of discharge opening on hard duct systems. This system can be used on all models installed horizontally providing ducting from rear of furnace without using side ducts. Use of a flexible mounting plate kit is available. See parts list.

1. Cut a 4” x 12” opening over floor ducting.

2. Remove three knockouts from rear of furnace.

3. Install duct adapters in each opening see Figure 7.

4. Place flex adapter plate with foam tape against hard ducting making sure openings line up.

5. With plate held in place, fasten plate to ducting using screws or staples as need to keep it flat.

6. Install three duct adapters into flex adapter plate.

7. Attach flexible ducting from furnace to flex adapter plate and secure ducting in place on both ends.

8. Additional ducting can be used to maintain correct static pressure or

16,000

20,000

25,000

30,000

35,000

1550*

1700*

1850*

WARNING

FIRE OR EXPLOSION

Never check for leaks with an open flame. Turn on the gas and apply soapy water to all joints to see if bubbles are formed.

WARNING

INJURY OR PROPERTY DAMAGE

 Label all wires before disconnecting for servicing. Wiring errors can

cause improper and dangerous operation. Verify proper operation after servicing.

 Disconnect electrical power before servicing.

CAUTION

PROPERTY DAMAGE

This connection is for low-voltage battery or direct current only. Do not connect to 120 or 240 volts AC.

Amps

3 4 5 6 7 8 9

Gage

Max. Length of SAE conductor (in feet) from source to device

as desired.

AIR FLOW CHECK

Appliances are tested to a temperature rise as specified on the Rating Plate. After installation of the furnace and duct system is completed, adjustments must be made to obtain a temperature rise as specified on the Rating Plate.

The table below is used as reference to maintain maximum operation of the appliance. If checking temperature rise is not possible, air flow measurements at each registers added together and divide the opening used from the furnace will give you air flow reading. This reading should not be less than the minimum in the table under your BTU appliance size.

If readings are below table values, air flow can be improved by adding ductwork. Check to make sure restrictions in the system are not present.

 *FPM= feet per minute readings

ELECTRICAL CONNECTIONS

POWER SUPPLY

Atwood Mobile Products highly recommends the use of an electronic (solid state) converter with clean power output. This will assure the life of the electronic controls and motor life could be extended beyond typical linear converter applications.

Conductor Sizing Table

– Maximum 10% Voltage Drop – (12VDC) Current draw (AMPS)

PROPANE GAS CONNECTION

1. Connect gas line to the fitting located on top right side of furnace or if is supplied with an extended manifold at the rear of the furnace.

2. Be sure all male pipe threads, other than flare fittings, are treated with a sealing compound resistant to the action of propane (LP) gas. DO NOT put sealing compound on flare fittings.

3. Use two wrenches to hold nut when tightening gas lines. DO NOT twist valve assembly.

 A 1/8” N.P.T. plug is accessible for test gauge connection on gas valve

assembly for pressure testing.

 A 3/8” flared fitting connection provided at gas control valve inlet for gas

supply connection to furnace. The gas supply line of the furnace must be of adequate size to provide 11” W.C. gas pressure. This pressure to be maintained under maximum flow conditions with all gas appliances in operation.

 If local codes allow the use of a flexible gas appliance connector, always

use a new listed connector. Do not use a connector, which has previously serviced another gas appliance.

1. Remove grommet plug from furnace.

2. Insert gas line through grommet plug (DO NOT CUT).

3. Connect gas line inside furnace casing immediately ahead of gas

control valve.

4. Connect gas line to brass fitting located on top or right side of

furnace.

5. Some models will have fittings at the rear outside of the casing.

6. Use two wrenches to hold brass fitting and flare nut when tightening

gas line to brass fitting. DO NOT twist valve assembly

Figure 7

 This furnace is designed for negative ground 12 volts DC only. DO

NOT attempt to alter furnace for a positive ground system or connect the furnace directly to 120 volts AC. Damage to furnace components will occur and warranty will be voided.

 Use a minimum of 18 GA wire to minimize voltage drop. Furnace

must be installed so electrical components are protected from water. To make electrical connections see wiring diagrams.

 For best furnace performance when power supply is from a

converter equipped with a charging port, wire converter to furnace parallel with battery. This provides consistent voltage to furnace, increasing component life, filtering power surges and AC spikes.

 All units are supplied with a power switch which when turned off

during servicing will remove power through furnace wiring. Switch must be in the ON position for furnace to operate.

 The direct high voltage spark ignition generates a radio frequency

that could cause interference with other microprocessor-based equipment. Locate equipment at least five feet (5’) from furnace location. If this distance cannot be maintained a shielded high voltage lead can be used.

1. Route wiring to top of furnace.

2. Connect red wire to positive side of power supply.

3. Connect black wire to grounded side of power supply.

4. Connect blue wire marked positive thermostat to + side wire of thermostat using 22-18 GA stranded wire.

5. Connect other blue wire to the other thermostat lead-using minimum 22-18 GA stranded wire.

THERMOSTAT INSTALLATION

 Thermostats are not supplied. To purchase a thermostat rated for

12VDC or 24VAC, Minimum 1 AMP rating, they can be ordered through Atwood.

 Be sure all electrical power has been disconnected from the air

conditioner, furnace, and the power supply.

 The thermostats are very sensitive. HANDLE WITH CARE AT ALL

TIMES.

 Pick a dry area where air circulation is good.  Do not install the thermostat where there are unusual heating

conditions: such as direct sunlight, heat producing appliances (television, radio, wall lamp, etc.) or a furnace or air conditioner output registers.

+ 13 hidden pages

Atwood AFMD16, AFMD20, AFMD25, AFMD30, AFMD35 Technical Installation Manual

Specifications and Main Features

Frequently Asked Questions

User Manual