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116986-01B

1

oPeRaTING HeaTeR

Continued

•  Timer: The timer mode (

TIMER

) operates 

much like the temperature mode above. The 

timer setting allows you to set specific times 

for on and off. (There are 2 burner on and 

2 burner off cycles every 24 hours.) If the 

reading for the nighttime temp. is "– – –", 

the motor will turn off the valve to standby 

pilot position and wait for the next burner 

on cycle. This display shows the setting tem-

perature every 30 seconds.

Setting the Temperature

•  Select the desired mode of operation (day or 

night) by pressing the 

SET

 button briefly.

•  Hold  the 

SET

  button  until  the  display 

flashes.

•  Set the temperature with the   or   (40°F 

is the minimum temperature).

•  Wait or press 

OFF

 to go to temperature 

control mode.

•  If temperature control in moon times should 

be off (lower battery consumption), decrease 

the night temperature until "– – –" appears 

on display.

Set Timer

•  Switch to timer mode by pressing the SET 

button briefly.

•  Press the 

SET

 button until 

P1

 

flashes.

•  Set the hours with   and minutes with   .

•  Press 

SET

 briefly for the next burner cycle 

time.

•  If all 4 times are set, pressing the 

OFF

 button 

or waiting will complete the programming.

Shutting Off Heater

Press OFF button on remote control to switch 

off main gas and pilot gas.

Shutting Off Burner Only (pilot stays lit)

Press   to decrease the flame height and shut 

off main burner.

MANUAL LIGHTING 

PROCEDURE

 WARNING: Manual lighting 

must be performed by a qualified 

service person.

The system has a "MANUAL OVERRIDE" 

feature that allows you to light with a match.

Lighting with a Match

1.  STOP!  Read  the  safety  information  on 

page 15 .

2.  Make  sure  equipment  shutoff  valve  is 

fully open.

3.  Turn motor-knob clockwise to 

 to 

OFF position.

4.  Wait (5) minutes to clear any gas and then 

smell for gas around heater and near floor. If 

you smell gas, STOP! follow "B" on page 15. 

If you do not smell gas, go to the next step.

5.  Make sure ON/OFF switch is in "–" (ON) 

position.

6.  MAN-knob  (valve)  in  MAN  position,  a 

metallic core is visible. (see Figure 18).

7.  Push and hold down metal core fully by us-

ing a non-sharp object such as a pen. This 

lets the pilot gas flow.

8.  Light  pilot  burner  with  a  match,  (see 

Figure 19).

9.  Continue holding down metal core for about 

10 seconds. Pilot should stay lit after releas-

ing metal core. If not, repeat step 1 thru 4.

10. Turn MAN-knob to ON position. This lets 

main gas flow.

11.  Turn Motor-knob to adjust flame. Knob has 

a slipping clutch that allows manual flame 

height adjustment as well as adjustment to 

pilot gas.

Figure 18 - Control Valve

Piezo 
Ignitor 
Tab

Metallic 
Core for 
Manual 
Ignition

Piezo Ignitor

ON/OFF Switch

Microswitch

MAN-Knob 
in Manual 
Position

Motor-
Knob 
in ON 
Position

Figure 19 - Pilot

Pilot Burner

Thermocouple

Summary of Contents for Design Dynamics VF-18N-MHD

Page 1: ...pliance Do not touch any electrical switch do not use any phone in your building Immediatelycallyourgassupplierfromaneighbor s phone Follow the gas supplier s instructions If you cannot reach your gas...

Page 2: ...air oxygen from the room in which it is installed Provi sions for adequate combustion and ventilation air must be provided Refer to Air for Combustion and Ventilation section on page 5 of this manual...

Page 3: ...a to cause cancer or birth defects or other reproductive harm IMPORTANT Read this owner s manualcarefullyandcompletely before trying to assemble operate or service this heater Improper use of this hea...

Page 4: ...eaterneedsfresh outsideairventilationto runproperly Thisheaterhasanoxygendepletion sensing ODS pilot light safety system The ODS shuts down the heater if not enough fresh air is available See Air for...

Page 5: ...ystem requires no matches or other source to light log set Air For Combustion and Ventilation WARNING This heater shall not be installed in a confined space or unusually tight con struction unless pro...

Page 6: ...grills between the rooms 1 Determine the volume of the space length x width x height Length x Width x Height __________cu ft volume of space Example Space size 20 ft length x 16 ft width x 8 ft ceilin...

Page 7: ...ption 3 Figure 2 Follow the National Fuel Gas Code ANSI Z223 1 NFPA 54 Section 5 3 Air for Combustion and Ventilation for required size of ventilation grills or ducts Figure 2 Ventilation Air from Ins...

Page 8: ...WARNING Never install the heater in a bedroom or bathroom in a recreational vehicle where curtains furniture cloth ing or other flammable objects are less than 42 from the front top or sides of the he...

Page 9: ...Size Height Depth Front Width Rear Width 18 20 14 35 22 1 2 24 20 14 35 22 1 2 MINIMUM FIREPLACE CLEARANCE TO COMBUSTIBLE MATERIALS Log Size 18 or 24 Side Wall 16 Ceiling 42 Floor 5 Measured at 14 dep...

Page 10: ...Minimum Mantel Clearances When Using Hood Minimum Noncombustible Material 8 Min 12 15 18 All minimum distances are in inches 20 2 1 2 6 8 10 12 Distances to Underside of Mantel Hood GA6050 GA6052 or G...

Page 11: ...ht remove the mantel Floor Clearances A If installing appliance on the floor level you must maintain the minimum distance of 14 to combustibles see Figure 8 B If combustible materials are less than 14...

Page 12: ...ction Purchase the optional CSA design certified equipment shutoff valve from your dealer See Accessories page 25 For propane LP units the installer must supply an external regulator The external regu...

Page 13: ...Purchase the optional CSA design certified equipment shutoff valve from your dealer See Accessories page 25 Minimum inlet pressure for purpose of input adjustment Figure 12 Gas Connection 3 Minimum C...

Page 14: ...e LP gas or opening main gas valve located on or near gas meter for natural gas or using compressed air 3 Check all joints from gas meter to equipment shutoff valvefornatural gas or propane LPsup ply...

Page 15: ...ARNING If fireplace has glass doors never operate this heater with glass doors closed If you op erateheaterwithdoorsclosed heat buildup inside fireplace willcauseglasstoburst Make suretherearenoobstru...

Page 16: ...off with ON OFFswitch thus disabling the remote hand set Setting The Display C 24h and F 12h Press and hold OFF and until display changes from F and 12 hour clock to C and 24 hour clock or vice versa...

Page 17: ...gas Shutting Off Burner Only pilot stays lit Press to decrease the flame height and shut off main burner MANUAL LIGHTING Procedure WARNING Manual lighting mustbeperformedbyaqualified service person Th...

Page 18: ...r knob to adjust flame Knob has a slipping clutch that allows manual flame height adjustment to turn gas off to appliance Shutting Off Heater Press OFF button on remote control to switch off main gas...

Page 19: ...to keep the primary air opening s of theburner s cleanmayresultin sooting and property damage Burner Injector Holder Air Inlet Hole The primary air inlet holes allow the proper amount of air to mix w...

Page 20: ...he burner Figure 25 Injector Holder on Front Burner Tube Burner Tube Primary Air Inlet Opening Injector Holder Injector Figure 24 Removing Front Log to Clean Front Burner Main Log Assembly Front Log A...

Page 21: ...ssure is too low 2 Burner orifice s clogged OBSERVED PROBLEM When and arepressedat the same time there is no spark at ODS pilot When and are pressed there is spark at ODS pilot but no ignition Burner...

Page 22: ...and let warm up for a minute 2 Operate burner until air is removed from line Have gas line checked by local natural or propane LP gas company 3 Observe minimum installation clearances see page 9 4 Cl...

Page 23: ...artially clogged 4 Thermostat on remote is satisfied 1 Gas leak See Warning statement at top of page 2 Control valve or gas control defective 1 Foreign matter between con trol valve and burner 2 Gas l...

Page 24: ...F Switch Soldered Cable Thermocurrent Cable 1 Motor Knob MAN Knob troubleshooting Continued POSSIBLE CAUSE Battery nearly down When signal appears the first time ap proximately 10 ignitions left Cable...

Page 25: ...ct authorized dealers of this product If they can t supply original replacement part s call DESA s Technical Service Department at 1 866 672 6040 When calling DESA have ready your name your address mo...

Page 26: ...llustrated Parts Breakdown Models VF 18N MHD VF 18P MHD VF 24N MHD and VF 24P MHD 1 2 3 4 5 25 22 7 8 18 9 6 10 11 26 34 23 12 21 20 29 28 29 28 27 24 27 24 22 13 19 14 32 30 15 15 15 15 15 15 31 15 1...

Page 27: ...01 117004 01 117004 01 Pilot Shield 1 20 099918 03 099918 02 099918 03 099918 02 Burner Regulator 1 21 116957 01 111803 03 116957 01 Air Shutter 1 22 111824 01 111824 01 111824 01 111824 01 Nut Sleeve...

Page 28: ...d by a qualified installer in accordance with all local codes and instructions furnished with the unit This warranty does not apply to parts that are not in original condition because of normal wear a...

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