Intertherm M1B Series, Installation Instructions Manual

28

oil Gun - Honeywell R7184 or Beckett 7505 

controls only - M5s series.

Burner does not start with a call for heat

•  Check the electrical supply to furnace.

•  Verify the furnace door switch is in the 

ON

 position.

•  Check  for  line  voltage  (115  VAC)  at  the  oil  primary 

control.

•  Check indicator LED with burner off, no call for heat (no 

flame). See 

Table 9, (page 29)

.

-  If green LED indicator is on, the cad cell is seeing 

stray light or the cad cell of controller is defective.

-  If green LED indicator is off, go immediately to step 

5.

-  If LED indicator is flashing (red or green on Beckett 

7505 control), refer to the next step 1 below - Reset 

primary control.

•  Jumper 

T

 to 

T

 terminals on primary control.

-  If burner starts, check thermostat or limit wiring 

connections.

-  If burner does not start, turn off power. Check all 

wiring connections.

-  If burner does not start, replace primary control.

Burner starts & then locks out on safety with 
Honeywell R7184 LED indicator flashing ½ 
second on, ½ second off. For Beckett 7505 
control, the red LED will flash

1. Reset primary control: To reset the control from (soft) 

lockout, the button needs only to be pressed and 

released. If the R7184 control is in restricted mode, 

press and hold the button for 45 seconds - until the LED 

flashes once. If the 7505 control is in restricted mode, 

press and hold the button in for 15 seconds until the 

red  turns off and the yellow LED turns on.

notE:

 Restricted Lockout: If the control locks out three 

times in a row without a complete heat cycle between 

attempts, the lockout becomes a restricted (hard) lockout.

2. If  the  LED  indicator  stops  flashing  and  the  ignition 

remains off, the primary control could be defective. If 

line voltage is present at the igniter terminals, and there 

is no ignition, the igniter is likely defective and needs 

to be replaced.

3. If the  stops flashing, burner turns on, but the control 

locks out again, check the cad cell. If the cad cell is 

operational, replace the primary control.

4. If  the  LED  continues  to  flash  at  the  interval  listed 

above, verify that the control is not in restricted mode. 

If in restricted mode, reset it. If not in restricted mode, 

replace the control.

5. If the (LED indicator for R7184 control; green LED for 

7505 control) stays off while the flame is on, check the 

cad cell sighting for view of the flame.

6. If the burner locks out, check the cad cell resistance. 

See 

Table 8

.

7. If the burner stays running, the system is operational.

8. If the (LED indicator for R7184 control; green LED for 

7505 control) is off, check the cad cell assembly after 

disconnecting the line voltage.

Burner will not start and the LED indicator
is flashing at 2 seconds on, 2 seconds off
for R7184 (or green LED is flashing for 7505)

•  Hold the reset button down for 1 - 2 seconds. If LED 

indicator continues to flash, wait for 60 - 70 seconds. If 

it still continues to flash, replace the primary control.

• 

Honeywell R7184 control

: To check cad cell resistance, 

press and release the button during the run mode, with 

the igniter off. The LED will flash to indicate the cad cell 

resistance. For proper burner operation, it is important 

that the cad cell resistance is under 1600 Ohms. For 

cad cell resistance, see 

Table 8

.

• 

Beckett 7505 control

: To check cad cell resistance, 

unplug the cad cell leads (yellow wires) from the control. 

Measure the resistance with a meter in the conventional 

way  (when  a  flame  is  present).  For  proper  burner 

operation, it is important that the cad cell resistance is 

under 1,600 Ohms.

Table 8

Table 8. cad cell Resistance when  

sensing flame

lED FlasHEs (oHMs)

caD cEll REsIstancE

1

0-400

2

400-800

3

800-1600

4

>1600