Hard Start / Kick Start Installation

Hard StartHard Starts

Description: This is the procedure and information for adding or replacing a hard start on an existing system. The specific unit in this example is a carrier brand ground level, split straight cool system. This procedure applies to almost every air conditioning and heat pump system on the market. Hard Start have a voltage rating and Horse power rating. A solid state hard start will cover a voltage range like 115V thur 288V with a HP range 4,000 to 120,000 BTU (1/2 thru 10 H.P.) so it is very hard to get the wrong one. Now I am not going to get into explaining or debate the pros or cons of solid state to the other types. What I am showing is what most air conditioning contractors would put on your system if not a 100%. This repair/upgrade is one of the simplest you can do.

What does a repair like this cost: Prices vary from area to area and company to company. A lot depends on the area you live in, the company, flat rate vs. time and material and many other factors. I have rarely seen prices under $200 and as high as $450. Hard start kits inexpensive and the installation straight forward. It is a great candidate for a do it yourself person or someone just looking to save a little cash.

Why do I need this repair/upgrade? A compressor needs the most starting torque in when it starts up. This also when compressor experiences the bulk of it wear and tear. A air conditioning system with a hard start installed on it has more starting torque. It starts faster and will have less starting up wear and tear. When we talk about wear and tear, it is something that adds up or weeks, months and years each time it starts. Without a hard start it adds up more quickly. The best example I can think of is in certain air conditioning configurations. The compressor starting under higher pressure differentials thus needing more torque. Put a compressor in with out a hard start and it starts intermittently if at all and greatly shorting the life of the compressor. Remember compressors rarely die they are kill!

Estimated Repair Time: 15 minutes


  • Nut Drivers/Screw Driver like this one

nut driver

  • Wire Stripper/Crimpers


  • Not required! Gloves I prefer mechanic gloves.
  • Not required! Volt Meter

Volt Meters


  • Hard Start

New kick start / hard start in package.

Repair Process:

  • condenser at side of house Locate your condenser aka the out door unit. Here is the one we are working on today. It about 10 years old. It is the one the builder put in so we can be sure it is not top of the line.
  • disconnect location Turn off off the disconnect. It is a good idea to check and make sure their is no power to the condenser with a voltage tester or meter. Here is our disconnect. It is a breaker type you man have the pull out type.
  • disconnect location Find and open the access panel. A good clue if you air conditioning system has more than one cover. It is the one with the electrical warning sticker on it. Here is the one for this unit. It is held on by two screws but a trick to easy removal is loosening this top two screws too.
  • Capacitor Terminals Locate the common terminal and compressor terminal. It is marked on capacitor next to the terminals. See the flyout images for reference.
  • Connected Hard start Connect the two wire on the hard start one to the common terminal and one to the compressor terminal. The hard start connectors have piggy back terminals if you find yourself one short spade post on the capacitor.
Installed Hard start Here is the most challenging. The mounting of the hard start. Now I have seen them just laying in units. I like to mount them. They give you a mounting ring right at the top. I usually just locate a mounting screw in a convenient location. Remove it and mount the unit using it. You can use a self tapping screw and mount it yourself any where. I rarely have to do this. I used an existing screw in this picture.
    • We are done now but some of the best advice I ever received was to measure twice and cut once. This applies here too. Double check all the wires are the connections are in the right place. Verify once more they are connected where they are suppose to be connected. Verify all the connections are tight. I like to give each wire a little tug at the base of the connection to verify this. All connections tight. Quick tip: If the your spade connectors are loose, pull them off, pinch them down just a little with your crimp ers and reconnect them. This tip alone can save numerous failures. Loose connections cause failures
    • Pulled In Contactor If all has gone well, the contactor should be pulled in. If your contactor is open, it would look like this. It is usually accompanied with a slight hum or buzz but not always. Most systems have a delay before turning the condenser on so be patient.
    • Put the condenser cover back on air conditioning condenser.
    • With the contactor pull in, turn the disconnect back on. The air conditioner will come on and run.

    You just saved big bucks and extended the life of you air conditioning system!