Owner's Manual

Dayton Operating Instructions and Parts Manual
6
Dayton Natural Gas
Construction Heater
®
3VH21
Troubleshooting Chart
Symptom
Possible Cause(s)
Corrective Action
Pilot fails to light
Pilot lights but goes out when automatic
control valve button is released
Maximum burn rate is low
Soot forming inside heater, flame 100%
yellow
Burn rate too high. Flames coming out of
emitter
1.Natural gas supply valve closed
2.Air in gas line
3.Blockage in pilot orifice
4.Piezo ignition system not sparking
1.Not enough warm-up time
2.Low gas pressure
3.Thermocouple loose or needs to be
replaced
4.Automatic control valve needs to be
replaced
1.Main burner valve not fully open
2.Plugged gas orifices
3.Low gas pressure
4.Low fuel supply
1.Main burner valve not open enough
2.Low fuel supply
1.Pressure too high
2.Unit connected to LP
1.Open natural gas supply valve slowly
2.Allow several minutes to purge air while
pilot button is depressed
3.Replace pilot orifice
4.Adjust ignitor electrode gap to .120".
Check wire lead for damage. Replace
piezo ignitor and/or ignitor electrode as
necessary
1.Relight, hold automatic control valve
button in 45 seconds
2.Check for proper gas supply
3.Tighten connection or replace thermo-
couple
4.Replace automatic control valve
1.Fully open main burner valve by turning
the valve handle towards ON position
until it stops
2.Replace gas orifice
3.Check gas supply; check regulator
output
4.Consult natural gas supplier
1.Adjust main burner valve slowly towards
ON position until flame has more blue
color
2.Consult natural gas supplier
1.Check inlet pressure. If over 4 psi adjust
or install regulator
2.Verify gas source. If connected to LP
gas, disconnect. Connect to natural gas
Never attempt to service heater while it is connected to natural gas supply, operating, or hot. Severe
burns can occur.