Vulcan-Hart VHX24G5, MHB24G manual Symptom Possible Causes

Models: VHX24G5 VHX24G MHB24G

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VHX SERIES STEAMER - TROUBLESHOOTING

SYMPTOM

 

 

POSSIBLE CAUSES

 

 

 

Blower operating, no pilot gas flow.

1.

Main gas supply turned OFF.

 

2.

Ignition module lockout. Turn power switch OFF for several

 

 

seconds then ON to reset the module.

 

3.

Air pressure switch:

 

 

A. Not mounted in true vertical position.

 

 

B.

Incorrect pressure setting.

 

 

C.

Malfunctioning switch.

 

4.

Malfunctioning Ignition module.

 

5.

Malfunctioning pilot gas valve.

 

6.

Blocked or dirty pilot gas orifice.

 

 

 

Pilot flame not proving or lighting main

1.

Gas not ON.

burner.

2.

Incorrect manifold pressure for pilot gas.

 

3.

Poor connection between igniter and ignition cable.

 

4.

Fouled spark igniter.

 

5.

Incorrect gap in spark igniter.

 

6.

Faulty igniter or cracked insulation.

 

7.

Improper ground.

 

8.

Low water level in boiler or boiler not filling.

 

9.

Flame sensing current too low.

 

10.

Cracked or incorrect burner head attachment.

 

11.

Incorrect igniter positioning.

 

12.

Incorrect pilot orifice.

 

 

 

Main burner not lighting correctly or

1.

Blocked or dirty air orifice on blower.

excessive ignition noise.

2.

Insufficient gas supply pressure.

 

3.

Incorrect gas pilot pressure.

 

4.

Incorrect gas manifold pressure.

 

5.

Pilot flame not sensing correctly.

 

6.

Burner tube insulation broken or deteriorated.

 

7.

Blocked or restricted flue.

 

8.

Incorrect pilot or main gas burner orifice size.

 

 

 

Excess combustion noise or combustion

1.

Blocked or dirty air orifice on blower.

induced harmonics.

2.

Incorrect gas manifold pressure.

 

3.

Insufficient gas supply pressure.

 

4.

Steam vapors introduced into blower inlet.

 

5.

Loose flue connections.

 

 

 

Boiler not maintaining set pressure

1.

Leaking boiler blowdown valve.

and/or excessive burner on time.

2.

Manual blowdown valve on water level probe housing open.

 

3.

Malfunctioning 13 psi overshoot relief valve.

 

4.

Low incoming gas supply pressure.

 

5.

Excessive load on steam outlet.

 

 

 

 

F24700 (October 2001)

 

Page 62 of 68

 

Page 62
Image 62
Vulcan-Hart VHX24G5, MHB24G manual Symptom Possible Causes