Desa H) AND VM42(B Manual Do Utilizador

108795-01M

For more information, visit www.desatech.com

TROUBLESHOOTING

 Before troubleshooting the system, make sure the gas shutoff valve is ON.

The two most common causes of a malfunctioning gas appliance are:
1. Loose wiring connections
2. Construction debris clogging the pilot and/or gas control valve filter

Pilot will not light

Pilot will not stay lit

No gas to burner, although wall switch and 

valve are set to the ON position

Frequent pilot outage

Pilot goes out when wall switch is ON

1.  No gas supply or shutoff valve is OFF

2.  Air in gas line

3.  Construction  debris  clogging  pilot 

orifice

4.  Low gas pressure

5.  Control valve knob is not on the PILOT 

position

6.  Kinked pilot line

7.  Bad valve

8.  Vent damper not fully open

1.  Loose wiring on thermopile to regulator 

valve. No millivolt current is being sent 

back to regulator

2.  If valve knob and wall switch are in the 

ON position, probable defective regula-

tor valve

3.  Vent damper not fully open

1.  Wall switch wires defective or too long

2.  Thermopile  not  generating  sufficient 

voltage

1.  Pilot  flame  may  be  too  low,  causing 

safety pilot to “drop out”

2.  Improper venting or excessive blockage

1.  Millivolt  output  on  thermopile  too 

high

1.  Check to see if you have gas supply

2.  Hold regulator control valve in the PI-

LOT position for 2 to 3 minutes to purge 

air. If you smell gas stop and wait for a 

few minutes before trying to light the 

fireplace

3.  Remove  debris  and  dirt,  inspect  and 

clean any other possible obstructions

4.  Contact your gas supplier

5.  Refer to section on pilot lighting

6.  Have  a  qualified  technician  replace 

pilot line

7.  Replace regulator valve (see Accesso-

ries, page 27)

8.  Open vent damper until fully locked in 

OPEN position 

1.  Check  wiring  connections.  Refer  to 

wiring diagram shown in Wall Switch 

Installation, page 10

2.  Have  a  qualified  technician  replace 

valve

3.  Open vent damper until fully locked in 

OPEN position

1.  Check electrical connections

2.  See Pilot will not stay lit, above

1.  Clean and adjust pilot flame for maxi-

mum  flame  impingement  on  thermo-

pile

2.  Have the vent system inspected, includ-

ing the termination cap. Remove any 

restriction or obstruction

1.  Replace thermopile