Contactor replacement

Discussion in 'HVAC Heating & Cooling' started by Rickcusaf, Jun 3, 2010.

  1. Rickcusaf

    Rickcusaf New Member

    Messages:
    19
    Location:
    Navarre FL
    I had the HVAC guy come out to my place and he told me the contactor and capacitor needed to be replaced. He wrote down the parts I needed and I ordered them from a local appliance store. The new contactor looks much different from my old one and I want to make sure I do it right.

    The two big questions I have are where my yellow wire which was attached to my HI9 goes and I also had a brown wire that was previously attached to the C terminal. My new one doesn't seem to have those labeled.

    Here is a picture of the old one
    [​IMG]
    The orientation of the old one is the same as in the picture.

    Here is the new one
    [​IMG]

    I forgot to mention that the HVAC guy said to pull the plug on the furnace before I swapped them out which I did do.

    I found a wiring guide for it and I believe I have it wired correctly, however when I plugged my furnace back in (I followed the instructions on the panel) the fan isn't turning on.
    Last edited: Jun 3, 2010
  2. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    One key characteristic of a contactor is the coil voltage....can be 24V, 120, or 240. Are you certain that the new contactor has the correct coil voltage.
  3. PEW

    PEW DIY Senior Member

    Messages:
    487
    Hard to tell from the photo, but it does not look like the low voltage control wires are attached to the contactor.
  4. Rickcusaf

    Rickcusaf New Member

    Messages:
    19
    Location:
    Navarre FL
    They were disconnected at the time, but I connected them shortly after posting. Right now my biggest problem is that my gas furnace isn't turning on at all. I've used a multi-meter to check my wall voltage and it's good and the next step was to check the slow-blow fuse and it seems a little discoloured, but didn't look bad. I took the fuse out though and tried a direct connection just to see if the lights would come on, but none of the lights on my circuit board are coming on.

    I have a Rheem Criterion II furnace. I've never had a problem with it until I unplugged it. Is there something special I need to do to restart it? I followed the directions on the front before I took it apart, but it doesn't look like power is even making it to the system.
  5. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,048
    Location:
    Cave Creek, Arizona
    HOW the wires are connected to ALL the contactor terminals is important, and since the wires have all be disconnected from the old one we cannot tell you the purpose of the various wires, or WHERE they attach to the new relay since we also do not have a diagram of that one. IT is hard to tell, but are the two lower connections tied together with that brass bar and the contactor just switching the upper wire? If, so either you have a 120v system and are switching the neutral, or you have a 240v system and are NOT breaking one of the two feeds. Neither of which is legal, proper, or safe. Probably the worst test to make is to remove/bypass a fuse and then activate the circuit board. If there were a problem, that could destroy the board before you could deactivate the power.
    Last edited: Jun 6, 2010
  6. Rickcusaf

    Rickcusaf New Member

    Messages:
    19
    Location:
    Navarre FL
    Here are pictures of my current setup for my contactor. The wiring mirrors how my old setup was with the exception of the two wires on the side. The original setup had the brown wire on the top portion and the yellow wire on the bottom one. Someone has said that I may need to build a jumper for this contactor, but I don't know where it would have to connect or if that person is even right.

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]
    Last edited: Jun 7, 2010
  7. Rat

    Rat New Member

    Messages:
    12
    Location:
    Bertram, Texas
    I see the problem.In this image you have the brown and yellow wire on the contactor hooked to the same side of the coil. These are low voltage wires (24 VAC) and one needs to be on one side of the coil and the other on the other side of the coil. The way you have them here is a direct short, which is why your furnace will no longer power up.

    In the furnace you have a step down transformer, 120V to 24V. Somewhere on the circuit board there is a 3 Amp automotive type fuse that is blown.

    Fix the wires on the contactor, one on each side, then replace the fuse, re-cycle the line power (switch) and it will work.
Similar Threads: Contactor replacement
Forum Title Date
HVAC Heating & Cooling Problem with Honeywell hydronic zone valve--replacement the only option? Jan 28, 2013
HVAC Heating & Cooling Replacement/Mae-up air Inlet Aug 24, 2012
HVAC Heating & Cooling Carrier 58SS replacement? Jun 4, 2012
HVAC Heating & Cooling Replacement for Honeywell L8148L-1005 Sep 19, 2011
HVAC Heating & Cooling GE 5KC39BG condenser motor replacement? Jun 13, 2010

Share This Page