Roberts Gorden UHD[X][S][R] 125 User Manual

33

NOTE: Minimum flame probe current 1 μA DC. Typical flame probe current 3-5 μA DC.

Repair or replace as 

required.

If problems persist, contact

Roberts-Gordon LLC at

www.rg-inc.com

Replace ignition control.

Use General

Troubleshooting section to 

trace the fault.

Heater Operating

No

Repair or replace as 

required.

Is inlet burner gas pressure 

correct? Is live and neutral 

polarity correct? Is

flame probe circuit correct?

Is there a current flowing in 

the flame probe circuit with 

no flame present?

Yes

No

Does “lockout” occur when

there is a flame present?

Yes

Is the connecting lead 

damaged? Is the flame probe 

damaged or touching earthed 

components?

No

Is the flame present and

at least 1 μA DC flame 

current?

Connect a DC ammeter in 

series with the flame probe.

Yes

No

Yes

Yes

No

To measure flame current, connect a 0 - 50 μA DC meter in series with the flame probe. If the meter 
reads negative values, then reverse the test leads.