Desa NTH100-2, NTH50-2, NTH70-2, NTH150-2, NTH35-2 User Manual

PORTABLE

FORCED

AIR HEATERS

OWNER’S MANUAL

Heater Sizes: 35,000 50,000 70,000

100,000 150,000 Btu/Hr

Models: NTH35-2, NTH50-2, NTH70-2, NTH100-2,

and NTH150-2

IMPORTANT: Read and understand this manual before assembling, starting or servicing heater. Improper use of heater can cause serious injury. Keep this manual for future reference.

PORTABLE FORCED AIR HEATERS

SAFETY INFORMATION

WARNINGS

IMPORTANT: Read this owner’s manual carefully and completely before trying to assemble, operate, or service this heater. Improper use of this heater can cause serious injury or death from burns, ﬁre, explosion, electrical shock, and carbon monoxide poisoning.

DANGER: Carbon monoxide

poisoning may lead to death!

Carbon Monoxide Poisoning: Early signs

of carbon monoxide poisoning resemble the ﬂu, with headaches, dizziness, and/or nausea. If you have these signs, the heater may not be working properly. Get fresh air at once! Have heater serviced. Some people are more affected by carbon monoxide than others. These include pregnant women, persons with heart or lung disease or anemia, those under the inﬂuence of alcohol, and those at high altitudes.

Make certain you read and understand all warnings. Keep this manual for reference. It is your guide to safe and proper operation of this heater.

• Use only kerosene or No. 1 fuel oil to avoid risk of ﬁre or explosion. Never use gasoline, naphtha, paint thinners, alcohol, or other highly ﬂammable fuels.

• Fueling a) Personnel involved with fueling shall

be qualified and thoroughly familiar with the manufacturer's instructions and applicable regulations regarding the safe fueling of heating units.

b) Only the type of fuel specified on the

heater's data plate shall be used.

c) All flame, including the pilot light, if

any, shall be extinguished and the heater allowed to cool, prior to fueling.

d) During fueling, all fuel lines and fuel-

line connections shall be inspected for leaks. Any leaks shall be repaired prior to returning the heater to service.

e) At no time shall more than one day's

supply of heater fuel be stored inside a building in the vicinity of the heater. Bulk fuel storage shall be outside the structure.

f) All fuel storage shall be located a

minimum of 762cm (25 feet) from heaters, torches, welding equipment, and similar sources of ignition (exception: the fuel reservoir integral with the heater unit).

g) Whenever possible, fuel storage shall

be confined to areas where floor penetrations do not permit fuel to drip onto or be ignited by a fire at lower elevation.

h) Fuel storage shall be in accordance

with the authority having jurisdiction.

• Never use heater where gasoline, paint thinner, or other highly ﬂammable vapors are present.

• Follow all local ordinances and codes when using heater.

• Heaters used in the vicinity of tarpaulins, canvas, or similar enclosure materials shall be located a safe distance from such materials. The recommended minimum safe distance is 304.8cm (10 feet). It is further recommended that these enclosure materials be of a fire retardant nature. These enclosure materials shall be securely fastened to prevent them from igniting or from upsetting the heater due to wind action.

• Use only in well-vented areas. Before using heater, provide at least a 2800 square cm (three-square-foot) opening of fresh, outside air for each 30 kw (100,000 Btu/Hr) of rating.

• Use only in places free of ﬂammable vapors or high dust content.

• Use only the electrical voltage and frequency speciﬁed on model plate.

• Use only a three-prong, grounded extension cord.

• Minimum heater clearances from combustibles:

Outlet: 250 cm (8 Ft.) Sides, Top, and Rear: 125 cm (4 Ft.)

• Locate heater on a stable and level surface if heater is hot or running or a ﬁre may occur.

• When moving or storing heater, keep heater in a level position or fuel spillage may occur.

• Keep children and animals away from heater.

• Unplug heater when not in use.

• When used with thermostat, heater may start anytime.

• Never use heater in living or sleeping areas.

• Never block air inlet (rear) or air outlet (front) of heater.

• Never move, handle, refuel, or service a hot, operating, or plugged-in heater.

• Never attach duct work to front or rear of heater.

105787

OWNER’S MANUAL

PRODUCT IDENTIFICATION

Hot Air Outlet

Upper Shell

Lower Shell

Fuel Tank

Side Cover

ON/OFF Switch with Light

Power Cord

Figure 1 - 35/50/70,000 Btu/Hr Models

Hot Air Outlet

Handle

Fan Guard

Air Filter End Cover

Fuel Cap

UNPACKING

1. Remove all packing items applied to

heater for shipment.

2. Remove all items from carton.

3. Check items for any shipping damage.

If heater is damaged, promptly inform dealer where you bought heater.

FUELS

WARNING: Use only kerosene or No. 1 fuel oil to avoid risk of ﬁre or explosion. Never use gasoline, naphtha, paint thinners, alcohol or other highly ﬂammable fuels.

Do not use heavy fuels such as No. 2 fuel oil or No. 2 Diesel. Using heavy fuels will result in:

• clogged fuel ﬁlter and nozzle

• use of non-toxic anti-icer in fuel during very cold weather

IMPORTANT:

container. Be sure storage container is clean. Foreign matter such as rust, dirt, or water will cause the flame-out control to shut down heater. Foreign matter may also require you to clean fuel system often.

Use a KEROSENE ONLY

Lower Shell

Fuel Cap

Side Cover

Figure 2 - 100/150,000 Btu/Hr Models

Upper Shell

Fan Guard

Fuel Tank

Power Cord

ON/OFF Switch with Light

105787

PORTABLE FORCED AIR HEATERS

ASSEMBLY

(FOR 100,000 AND 150,000 BTU/HR MODELS ONLY)

These models are furnished with wheels and handles. Wheels, handles, and the mounting hardware are found in the shipping carton.

Tools Needed

• Medium Phillips Screwdriver

• 3/8" Open or Adjustable Wrench

• Hammer

1. Slide axle through wheel support frame. Install wheels on axle.

IMPORTANT:

point extended hub of wheels toward wheel support frame (see Figure 3).

When installing wheels,

2. Place cap nuts on axle ends. Gently tap with hammer to secure.

3. Place heater on wheel support frame. Make sure air inlet end (rear) of heater is over wheels. Line up holes on fuel tank ﬂange with holes on wheel support frame.

4. Place front handle and rear handle on top of fuel tank ﬂange. Insert screws through handles, fuel tank ﬂange, and wheel support frame. Attach nut ﬁnger tight after each screw is inserted.

5. After all screws are inserted, tighten nuts ﬁrmly.

Front Handle

VENTILATION

WARNING: Follow the minimum fresh, outside air ventilation requirements. If proper fresh, outside air ventilation is not provided, carbon monoxide poisoning can occur. Provide proper fresh, outside air ventilation before running heater.

Provide a fresh air opening of at least 2800 square cm (three square feet) for each 30kw (100,000 Btu/Hr) rating. Provide extra fresh air if more heaters are being used.

Example:

requires one of the following:

• a two-car garage door [4.9 meter (16 feet) opening] raised 9 cm (3.5 inches)

• a single-car garage door [2.75 meter (9 feet) opening] raised 15.25 cm (6 inches)

• two, 76 cm (30 inch) windows raised 28 cm (11 inches)

A 44kw (150,000 Btu/Hr) heater

Screw

Hot Air Outlet

Fuel Tank Flange

Wheel Support Frame

Wheel

Cap Nut

Figure 3 - Wheel and Handle Assembly

Nut

Axle

Rear Handle

Air Inlet

Extended Hub

105787

OWNER’S MANUAL

THEORY OF OPERATION

The Fuel System: The air pump forces air through the air line. The air is then pushed through the burner head nozzle. This air causes fuel to lift from the tank. A ﬁne mist of fuel is sprayed into the combustion chamber.

The Air System: The motor turns the fan.

The fan pushes air into and around the combustion chamber. This air is heated and provides a stream of clean, hot air.

The Ignition System: The ignition control assembly provides power to the ignitor. This ignites the fuel/air mixture in the combustion chamber.

The Flame-Out Control System: This sys-

tem causes the heater to shut down if the ﬂame goes out.

Combustion Chamber

Ignitor

OPERATION

WARNING: Review and un-

derstand the warnings in the

Safety Information

2. They are needed to safely operate this heater. Follow all local codes when using this heater.

TO START HEATER

1. Follow all ventilation and safety information.

2. Fill fuel tank with kerosene or No. 1 fuel oil.

3. Attach fuel cap.

4. Plug power cord of heater into standard 240 volt/50 hertz, grounded (earthed) outlet. Use an extension cord if needed. Use only a three-prong, grounded (earthed) extension cord.

Motor

Fan

section, page

Air Pump

Air Intake Filter

EXTENSION CORD WIRE SIZE REQUIREMENTS

Up to 30.5 meters (100 feet) long, use 1.0 mm2 (16 AWG) conductor

30.6 to 61 meters (101 to 200 feet) long, use

1.5 mm

(14 AWG) conductor

Push ON/OFF switch to ON (|) position and heater should start in 5 seconds. If ON/OFF switch light does not come on or heater does not start, see Troubleshooting (pages 6 and 7).

TO STOP HEATER

Push ON/OFF switch to OFF (O)position.

TO RESET HEATER

1. Push ON/OFF switch to OFF (O) position and wait 10 seconds (2 minutes if heater has been running).

2. Repeat steps under To Start Heater.

ON/OFF Switch

with Light

Clean Heated Air Out

Fuel Tank

Figure 4 - Cross Section Operational View

Nozzle

Air For Fuel System

Fuel Filter

Air Line To Burner

Air For Combustion And Heating

Cool Air In

Air Output Filter

Ignition Control Assembly

Fuel

Figure 5 - ON/OFF Switch, 35/50/70,000 Btu/Hr Models

ON/OFF Switch

with Light

Figure 6 - ON/OFF Switch, 100/150,000 Btu/Hr Models

105787

PORTABLE FORCED AIR HEATERS

STORING, TRANSPORTING, OR SHIPPING

Note:

If shipping, transport companies re-

quire fuel tanks to be empty.

1. Drain fuel tank.

Note:

Some models have drain plug on underside of fuel tank. If so, remove drain plug to drain all fuel. If heater does not have drain plug, drain fuel through fuel cap opening. Be sure all fuel is removed.

2. Replace drain plug if provided.

3. If any debris is noted in old fuel, add 1 or 2 quarts of clean kerosene to tank, stir, and drain again. This will prevent excess debris from clogging filters during future use.

4. Replace fuel cap or drain plug. Properly dispose of old and dirty fuel. Check with local automotive service stations that recycle oil.

5. If storing, store heater in dry place. Make sure storage place is free of dust and corrosive fumes.

IMPORTANT:

summer months for use during next heating season. Using old fuel could damage heater.

Do not store kerosene over

PREVENTATIVE MAINTENANCE SCHEDULE

Item

Fuel tank

Air output and lint ﬁlters

Air intake ﬁlter

Fuel ﬁlter

Ignitor Fan blades

Motor

How Often

Flush every 150-200 hours of operation or as needed

Replace every 500 hours of operation or once a year

Wash and dry with soap and water every 500 hours of operation or as needed

Clean twice a heating season or as needed

No maintenance required Clean every season or as

needed Not required/permanently lu-

bricated

WARNING: Never service heater while it is plugged in, operating, or hot. Severe burns and electrical shock can occur.

How To

See Storing, Transporting, or Ship- ping

See Air Output, Air Intake, and Lint Filters, page 10

See Fuel Filter, page 8

See Fan, page 13

TROUBLESHOOTING

FAULT CONDITION

Motor does not start five seconds after heater is plugged in (ON/OFF switch light remains on)

WARNING: Never service heater while it is plugged in, operating, or

hot. Severe burns and electrical shock can occur.

ATTENTION:

the light in the ON/OFF switch to troubleshoot the fault condition.

POSSIBLE CAUSE

1. Bad electrical connection between motor and ignition control assembly or ignition control assembly and power cord

2. Binding pump rotor

3. Defective ignition control assembly

4. Defective motor

The ignition control has built-in protection against current overloads. Use

REMEDY

1. Check all electrical connections. See Wiring Diagram, page 25

WARNING: High voltage!

2. If fan does not turn freely, see Pump Rotor, page 12

3. Replace ignition control assembly

4. Replace motor

105787

TROUBLESHOOTING

Continued

OWNER’S MANUAL

FAULT CONDITION

Motor starts and runs but heater does not ignite (ON/OFF switch light remains on)

Heater ignites but ignition control assembly shuts heater off after a short period of time (ON/OFF switch light remains on)

POSSIBLE CAUSE

1. No fuel in tank

2. Pump pressure incorrect

3. Dirty fuel ﬁlter

4. Obstruction in nozzle assembly

5. Water in fuel tank

WARNING: High voltage!

6. Bad electrical connection between ignitor and ignition control assembly

7. Defective ignitor

8. Defective ignition control assembly

1. Pump pressure incorrect

2. Dirty air intake, air output, and/or lint filter

3. Dirty fuel ﬁlter

4. Obstruction in nozzle assembly

5. Photocell assembly not properly installed (not seeing the flame)

WARNING: High voltage!

REMEDY

1. Fill tank with kerosene

2. See Pump Pr essure Adjustment, page 10

3. See Fuel Filter, page 8

4. See Nozzle Assembly, page 11

5. Drain and ﬂush fuel tank with clean kerosene. See Storing, Transporting, or Shipping, page 6

6. Check electrical connections. See Wiring Diagram, page 25

7. Replace ignitor, see page 9

8. Replace ignition control assembly

1. See Pump Pr essure Adjustment, page 10

2. See Air Output, Air Intake, and Lint Filters, page 10

3. See Fuel Filter, page 8

4. See Nozzle Assembly, page 11

5. Make sure photocell boot is properly seated in bracket

ON/OFF switch light does not come on when switch is turned to the ON (|) position and heater does not start

ON/OFF switch light comes on when switch is turned to the ON (|) position but turns off after five seconds

6. Dirty photocell lens

7. Bad electrical connection between photocell and ignition control assembly

8. Defective photocell

9. Defective ignition control assembly

1. No power to heater

WARNING: High voltage!

2. Bad electrical connections

3. Electrical short in ignitor

1. Electrical short in motor

WARNING: High voltage!

6. Clean photocell lens

7. Check electrical connections. See Wiring Diagram, page 25

8. Replace photocell

9. Replace ignition control assembly

1. Verify that power cord is plugged into an electrical outlet and that the circuit breaker in the electral panel is reset

2. Check electrical wiring and connections. See W iring Diagram, page 25

3. Check ignitor wiring. If no problems are found, replace ignitor (see page 9)

1. Check motor wiring. If no problems are found, replace motor

105787

PORTABLE FORCED AIR HEATERS

SERVICE PROCEDURES

WARNING: Never service heater while it is plugged in, operating, or hot. Severe burns and electrical shock can occur.

UPPER SHELL REMOVAL

1. Remove screws and lock washers along each side of heater using 5/16" nutdriver. These screws attach upper and lower shells together.

2. Lift upper shell off.

3. Remove fan guard.

FUEL FILTER

(35/50/70,000 Btu/Hr Models)

1. Remove side cover screws using 5/16" nut-driver.

2. Remove side cover.

3. Pull rubber fuel line off fuel ﬁlter neck.

4. Carefully pry bushing and fuel ﬁlter out of fuel tank.

5. W ash fuel ﬁlter with clean fuel and replace in tank.

6. Attach rubber fuel line to fuel ﬁlter neck.

7. Replace side cover.

FUEL FILTER

(100/150,000 Btu/Hr Models)

1. Remove side cover screws using 5/16" nut-driver.

2. Remove side cover.

3. Pull upper fuel line off fuel ﬁlter neck.

4. Carefully pry bushing, lower fuel line, and fuel ﬁlter out of fuel tank.

5. W ash fuel ﬁlter with clean fuel and replace in tank.

6. Attach upper fuel line to fuel ﬁlter neck.

7. Replace side cover.

Upper Shell

Fan Guard

Figure 7 - Upper Shell Removal, 35/50/ 70,000 Btu/Hr Models

Fuel Filter

Side Cover

Figure 9 - Fuel Filter Removal, 35/50/70,000 Btu/Hr Models

Fuel Filter, Bushing, and Lower Fuel Line

Upper Shell

Figure 8 - Upper Shell Removal, 100/ 150,000 Btu/Hr Models

Fuel Line

Fan Guard

Upper Fuel Line

Side Cover

Figure 10 - Fuel Filter Removal, 100/150,000 Btu/Hr Models

105787

OWNER’S MANUAL

SERVICE PROCEDURES

Continued

IGNITOR

1. Remove upper shell and fan guard (see page 8).

2. Remove fan (see page 13).

3. Remove 4 side cover screws with a 5/16" nut driver. Remove side cover (see Figure 9 or 10, page 8).

4. Disconnect ignitor wires (black) from ignition control assembly (see Figure

11). Pull the ignitor wires up through the hole in the lower shell.

5. Disconnect fuel line hose and air line hose. Remove photocell from photocell bracket (see Figure 11).

Combustion Chamber

Nozzle Adapter Bracket

Ignitor

6. Remove combustion chamber. Stand combustion chamber on end with nozzle adapter bracket on top (see Figure 12).

7. Remove ignitor screw with a 1/4" nut driver. Carefully remove ignitor from nozzle adapter bracket.

CAUTION: Do not bend or strike

ignitor element. Handle with care.

8. Carefully remove replacement ignitor from styrofoam packing.

9. Carefully guide ignitor into opening in nozzle adapter bracket. Do not strike ignitor element. Attach ignitor to nozzle adapter bracket with screw using a 1/4" nut driver (see Figure 12). T orque .90 to 1.69 N-m (8 to 15 in-lbs). Do not over torque.

Ignitor Screw/Washer Assembly

10. Replace combustion chamber.

11. Route the ignitor wires back down through the hole in the lower shell. Connect wires to the ignition control assembly.

12. Replace side cover (see Figure 9 or 10, page 8).

13. Connect and route fuel line hose and air line hose to burner head. See Fuel

and Air Line Replacement and Proper Routing, page 11.

14. Replace photocell in photocell bracket. Route wires as shown in either Figure 17, 18, or 19, page 11.

15. Replace fan (see page 13).

16. Replace fan guard and upper shell (see page 8).

Air Line Hose

Fuel Line Hose

Photocell Bracket

Photocell Assembly

Side Cover

Figure 11 - Disconnecting Ignitor Wires from Ignition Control Assembly

Ignitor Wires

Ignition Control Assembly

Ignitor Element

Photocell Bracket

Combustion Chamber

Figure 12 - Ignitor Replacement

Nozzle Adapter Bracket Opening

Nozzle Adapter Bracket

Ignitor

105787

Continued

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