Desa VN20BT, VP30BT, VP20BT, VN30BT installation manual Inspecting Heater

Page 15

OPERATING HEATER

Continued

8.Turn control knob counterclockwise to desired heating level. The main burner should light. Set control knob to any heat level between 1 and 5.

CAUTION: Do not try to ad- just heating levels by using the equipment shutoff valve.

TO TURN OFF GAS

TO APPLIANCE

Shutting Off Heater

1.Turn control knob clockwise to the OFF position.

2.Turn off all electric power to the appliance if service is to be performed.

Shutting Off Burner Only (pilot stays lit)

Turn control knob clockwise to the PILOT position.

THERMOSTAT

CONTROL OPERATION

The thermostatic control used on these models differs from standard thermostats. Standard thermostats simply turn on and off the burner. The thermostat used on this heater senses the room temperature. The thermostat adjusts the amount of gas flow to the burner. This increases or decreases the burner flame height. At times the room may exceed the set temperature. If so, the burner will shut off. The burner will cycle back on when room temperature drops below the set temperature. The control knob can be set to any heat level between 1 and 5. Selecting the 5 setting will cause the burner to remain fully on without modulating down in most cases.

Note: The thermostat sensing bulb measures the temperature of air near the heater cabinet. This may not always agree with room tem- perature (depending on housing construction, installation location, room size, open air tem- peratures, etc.). Frequent use of your heater will let you determine your own comfort levels.

MANUAL LIGHTING

PROCEDURE

1.Remove front panel (see Figure 7, page 9).

2.Follow steps 1 through 5 under Lighting Instructions, page 14.

3.With control knob pressed in, strike match. Hold match to pilot until pilot lights.

4.Keep control knob pressed in for 30 seconds after lighting pilot. After 30 seconds, release control knob. Now follow step 8, under Lighting Instructions, pages 14 and 15.

5.Replace front panel.

INSPECTING HEATER

Check pilot flame pattern and burner flame pat- tern often.

PILOT FLAME PATTERN

Figure 21 shows a correct pilot flame pattern. Figure 22 shows an incorrect pilot flame pattern. The incor- rect pilot flame is not touching the thermocouple. This will cause the thermocouple to cool. When the thermocouple cools, the heater will shut down.

If pilot flame pattern is incorrect, as shown in Figure 22

turn heater off (see To Turn Off Gas to Appli- ance)

see Troubleshooting, page 18

Note: The pilot flame on natural gas units will have a slight curve, but flame should be blue and

Thermocouple

Blue Flame

Pilot Burner

Figure 21 - Correct Pilot Flame Pattern

Thermocouple

Yellow Flame

Pilot Burner

Figure 22 - Incorrect Pilot Flame Pattern

BURNER FLAME PATTERN

WARNING: If yellow tipping occurs, your heater could pro- duce increased levels of carbon monoxide.

NOTICE: Do not mistake orange flames with yellow tipping. Dirt or other fine particles enter the heater and burn causing brief patches of orange flame.

107886-01J

www.desatech.com

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Contents What to do if YOU Smell GAS Table of Contents Safety Information Product Features Local CodesUnpacking Confined and Unconfined Space AIR for Combustion VentilationProviding Adequate Ventilation Unusually Tight ConstructionDetermining if You Have a Confined or Unconfined Space Determining FRESH-AIR Flow for Heater LocationVentilation Air From Inside Building InstallationVentilation AIR Check GAS TypeLocating Heater Installation ItemsThermostat Sensing Bulb Installing Heater to WallInstalling Bottom Mounting Screws Attaching To Wall Anchor MethodPlacing Heater On Mounting Bracket Mounting Base Feet to Heater Connecting to GAS SupplyMounting Base Feet to Floor Where required by local code Mounting Heater to FloorVN30BT, VP30BT 1/2 or greater Checking GAS ConnectionsTest Pressures Equal To or Less Than 1/2 Psig 3.5 kPa Pressure Testing Heater GAS ConnectionsFor Your Safety Read Before Lighting Operating HeaterLighting Instructions Inspecting Heater Cabinet Cleaning MaintenanceODS/PILOT and Burner Burner Pilot AIR InletService Publications SpecificationsService Hints Technical ServiceObserved Problem Possible Cause Remedy TroubleshootingSee Cleaning and Mainte Statement above Gas leak. See WarningAccessories Replacement PartsModels VN20BT, VP20BT VN30BT, VP30BT Illustrated Parts BreakdownNJF 8C Parts ListWarranty Information Keep this WarrantyLimited Warranty VENT-FREE Residential GAS Heaters