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Color code for 7284 primary control

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tcabana94
tcabana94 Member Posts: 19
Hi I dumbly was trying to connect a new igniter to my system and I was rushing through trying to undo the connections after a long day of working two jobs and while doing so I did not take a picture of the wiring when unscrewing the wing nuts I've tried to reconnect the best I could but with no luck I thought I had it at one point but the furnace wouldn't light it just stayed on standby then I checked my connections and tried again and when I went to start it. It only told me cad cell 0 ohm even though the cad cell was working prior and was properly connected together. I can take pictures if need be it's a miller furnace with a Beckett burner I changed the igniter cause when I tested the coils it only arched when I literally put the screw driver directly on it. Sorry for the lengthy post if anyone could help if you need more info or want pics of the wires I have let me know and thank you again.

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  • STEVEusaPA
    STEVEusaPA Member Posts: 6,505
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    Limit, red on Limit
    Black wire, power on L1
    Blue w/ white stripe (from ignitor) on Ignitor
    Purple wire from oil valve on Oil Valve
    Wire from motor, on Motor
    All white neutrals on L2's
    2 yellow wire on Cad cell
    …Unless you have a board, then take a picture and we’ll try it again.

    There was an error rendering this rich post.

    tcabana94
  • tcabana94
    tcabana94 Member Posts: 19
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    So on mine there a power cable that's split under the primary box with both leads stripped it leads back to the box with the door switch on it would you have any clue what to hook both bother ends to sorry for getting back to you on Christmas day 
  • tcabana94
    tcabana94 Member Posts: 19
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    i hope these photos are clear enough terrible lighting in area where furnace is
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,849
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    If it is some type of door safety switch just connect the black power wire to 1 wire and connect the other wire to where the black power wire would go
  • tcabana94
    tcabana94 Member Posts: 19
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    No power to furnance wondering if the split power cable and power for L1 are supposed to be tied first time ever getting into this even tho I deliver propane and oil for a living
  • Big Ed_4
    Big Ed_4 Member Posts: 2,835
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    Depends , ok you say there is a door switch ? Make sure and put aside .... The leads under the box , are there two hots and a neutral or just one hot from the limit and a neutral . Some system keep the primary control energized all the time though L1 or the black and the limit would shut off control though the red limit which would be two hots and a neutral .. If you have just a hot (which is though a limit) and a neutral then the Red limit and black L1 needs to be wired together ... The door switch would be wired in series before ....

    Now this is important do not walk away onced started make sure burner shuts off on temperature . To make sure no limit was bypassed .

    There was an error rendering this rich post.

  • tcabana94
    tcabana94 Member Posts: 19
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    Left all connections undone in photos except for blue from igniter only power coming into box I can see is from that split end cable which plugs into the bottom of the door switch.
  • Big Ed_4
    Big Ed_4 Member Posts: 2,835
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    You need to find out which wire on that split cable is 110V or hot , connect to Red and black , purple connect to pump selonode , Orange to motor , Yellows to yellows , ingniter to blue ..... The neutrals , control , igniter , pump ,motor tie into the neutral on that split cable

    There was an error rendering this rich post.

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,176
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    That looks like a mobile home furnace. was your old control the same type control? or was your old control a R8184G ?

    The wiring for the control is like this: The black cord, that reminds you of a 2 wire extension cord has a code. The conductor with ribbed insulation is the white wire on the R7284 also known an L2. All the other white wires get connected there also. The ignitor, the motor and the valve white wires alr all connected under one wire nut.
    The black conductor with the smooth insulation goes to Red and Black wires that go to L1 and Limit. All 3 wires go under one wire nut.

    The Motor (usually orange) goes the black wire on your motor

    The Valve (usually purple) wire goes to the purple wire on your valve

    The Ignition (Usually Blue) wire goes to the Blue Wire on the ignition.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,176
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    Here is a diagram form a course I taught on oil burners. the confusing part when these controls came out was that both Limit and L1 needed power at the same time (Red and Black)




    I remember sending a new control back after connecting the limit only with a unsuccessful repair. When the same thing happened the second time I tried to use these new fangled controls, I decided to read the instructions. That is when I discovered you need to connect both the red and black to the power L1.

    It makes sense to me now, But your first time is always a learning experience ...in more ways than one LOL

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • tcabana94
    tcabana94 Member Posts: 19
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    It is an old mobile home furnace this was the primary control box that was on it when I moved in over a year ago
  • tcabana94
    tcabana94 Member Posts: 19
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    Just got home and reconnected it the wires hit the emergency off switch back to on and pulled the door switch to service mode got no response from the primary control box disconnected the wires again separated the two black wires double checked to make sure I had live power going to the furnace checked both ribbed and unribbed wire and got no electric response like it was dead could I have fried the wire when I was attempting to connect it myself it did arch the night I tried before I went to bed.
  • tcabana94
    tcabana94 Member Posts: 19
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    Took the off the cover on the door switch and the bottom lead doesn't look right to me wanted to know if it looked toasted to you guys as well
  • tcabana94
    tcabana94 Member Posts: 19
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    Took the cover off*
  • tcabana94
    tcabana94 Member Posts: 19
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    That lead is toast. Was wondering if this wire and lead combo could be bought at like home Depot or Ace hardware or something or if I had to buy the wire strip it and tie the lead onto it 


  • pecmsg
    pecmsg Member Posts: 4,968
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    That contact is still good but should be replaced. The hardware store will have a replacement. 
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,176
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    If you are still having problems You need to know if there 110V. (120V.) between the Hot and Common. Do you have a voltage tester? When the furnace is cold, there should be 110-120V AC at the black extension cord wire that connects to L1 and L2 on the Honeywell Primary Control L7284. That is your first stop. if you don't power the control, then you won't operate the burner.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,176
    edited December 2021
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    What model number is your Furnace? and what is the part number of the white control in the photo showing the compromised wire connector?

    once we have that info we can help trace the electrical wiring diagram like this illustration of a similar furnace.

    See the wiring diagram of a Model CMF 80

    If we look as if electric travels in one direction, has a starting point on a black wire called L1 and must return to a white wire called Common or L2 (Remember, the actual electric is colorblind. The colors are not always correct but used to make identification easier.) then we can see how the electric current travels thru the wire to power each LOAD. (A LOAD is the user of electricity like a light bulb or motor or relay coil)

    See the L1 where the Black wire starts (I painted it light blue) The electric travels to the Limit / Fan control (that may be the white control box in tour photo of the defective wire) where it goes in 2 directions, to the burner plug and to the fan motor. There the electric current flows to the AUX Limit. (I painted that a darker blue) I want to make a special note here that this AUX Limit is located on the blower deck and may have a manual reset button between the wire connectors make sure that button is not tripped. i have placed the AUX Limit in a green box on the diagram

    From there the electric current flows to the door switch. (That is a darker blue.)

    From the door switch, it goes to the burner plug. (That is a deeper blue/violet color in the diagram.)

    From there, the burner is receiving power and sends the electric on its way to the return path back to L2 or common.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • tcabana94
    tcabana94 Member Posts: 19
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    Replaced the lead and reconnected the wires got power back to the primary the screen reads cad cell 0 ohms I hold the reset it counts down from 3 and it goes back to the 0 ohm screen the cad cell was working before