Question about Air Conditioners

3 Answers

Heat Pump hums, clicks and does not come on sometimes

Lennox Heat Pump- M/N 12hpbz4-4p Excuse me for waiting so long to find solution for problem but I tend to procrastinate. This problem has gone on for a year or so. Cold weather now and the heat pump sometimes makes a loud click when turning on and off. Also, when the air handler comes on inside, the heat pump does not always come on. Instead it makes a loud hum but fan does not switch on.Eventually it does. Twice I went out and shook it and fan came on but i am not sure if it was going to come on anyway and that was just a coincedence. I called Lennox today and to see if I could talk to a tech but could not get past receptionist. She told me that outside unit should come on at same time as inside air handler. Is this true?
Had it serviced last week. Repairman took out indoor coil (which was filthy) and cleaned it outside with solution. Also cleaned outside coils with solution. Heat pump would not make noise of course and fan came on with him here but it was also a warm day if that matters. He turned it on and off a few times. Said he thought it was going to be the contacts, but he said if it was then they would of made noise while he was here and they usually go out for good. He is hinting that it might be motor but when it runs, it sounds great and he did not say anything like it sounded like it was going bad. As mentioned the clicking noise and fan not working while it hums happens often but not all the time. Not sure if I am imagining that it happens more in colder and warmer weather or just happens that I am outside and happen to hear it.

Posted by on

  • 5 more comments 
  • gulfbeach47 Jan 08, 2009

    I am guessing that the start capasitor is what is stopping the fan from coming on?

    Contactor chattering? Did you mean the contractor (technician) or is that a part? If it is the part, would that be what's making the loud clcik at times when heat pump come on and shuts off?

    Also, was the lady correct at Lennox when she said outside unit should come on at same time as indoor handler?

  • gulfbeach47 Jan 08, 2009

    The click or metal ping sound happens when unit comes on and shuts off. When there is a hum, the motor or something in there is making a loud hum but fan blades are not turning. Then there is a sound when fan comes on. Is it just a coincidence that fan comes on when I shake the unit? I can feel the heat coming up from above fans when it is not running. Will the motor burn out when it is making this hum and fan not moving? Can the tech test the start capasitor or do you just switch it out and hope that is the problem?

  • gulfbeach47 Jan 08, 2009

    oops...not sure if last post went through. I pointed mouse over where i was printing and everything vanished. For some reason you cannot copy/paste here.

  • gulfbeach47 Jan 08, 2009

    I guess my other reply went into cyberspace. I hear a ping or metal sounding click when fan comes on and when it shuts off intermittently. Not all the time. Seems like it happens more in colder weather but not 100% sure about that. Happens in heat of summer too. Fan is facing up, so when my air handler comes on and I hear the hum outside, I go out and look and if it is still humming, then the fan is not turning. But at the same time there is noise coming from in the heat pump (maybe the motor humming?) As I look down I feel heat and see steam coming up from unit. I don't feel any heat coming from sides of unit that I have noticed. Don't know about air pressure leaking out sound. It would have to be loud for me to notice because of some hearing loss. Defrost mode? If it has not been running long would it be going into defrost mode? It has been running for a few hours tonight and no hums or click that I have noticed so far. If fan is not turning and unit is humming can motor burn up unless it is defrost mode as you suggest? Is there directions on how to change out a start capacitor some where if that is the problem. And is it hard to get to...especially for someone that has no experience? How much does a start capacitor cost usually?

  • gulfbeach47 Jan 08, 2009

    You wrote> "some brands of units have a delay in the outside units board to stop it from starting at the exact same time as the air handler." Would the brand with the delay sometimes let heat pump start at same time and other times, not let it start for awhile and be humming during this time? Ok. so all tonight it has not made the metal click sound and seems to be running fine, but it will happen again. So, would you be leaning towards replacing start capacitor or ? I forgot to ask last reply is here a way ot test the start capacitor? Kind of unsure what to do about the problem. I hate for the motor to burn up. I am not sure if me technician knew what he was doing. He did not offer any advice. Just $165.00 for cleaning and looking for problem. last time I got the cleaning for $75.00 but it was a friend of a friend.

  • Anonymous Jan 25, 2009

    Steam comes out of the outside unit, and sometimes the fan and green light stays on for a while on the thermostat inside, is this normal?

  • dwkcool May 11, 2010

    sounds like you might have a start capasitor going bad and a contactor chattering

×

3 Answers

  • Level 2:

    An expert who has achieved level 2 by getting 100 points

    MVP:

    An expert that got 5 achievements.

    Governor:

    An expert whose answer got voted for 20 times.

    Hot-Shot:

    An expert who has answered 20 questions.

  • Expert
  • 96 Answers

Yes the start capasitor starts the fan motor and the contactor pulls together when the t-stat tells it to start and it has a spring in it that gets week , some brands of units have a delay in the outside units board to stop it from starting at the exact same time as the airhandler

Posted on Jan 08, 2009

  • 2 more comments 
  • dwkcool Jan 08, 2009

    is this happening when it is very cold out and do you feel the heat from down by the fan area, plus when the fan kicks on does the noise you hear sound like air presure leaking out

  • dwkcool Jan 08, 2009

    if you got my last posted and all of that is true ,the unit is just going into defrost mode and there is nothing wrong with it

  • dwkcool Jan 08, 2009

    if it"s not in defrost mode yes it can burn the motor up and the capasitor can hold anywhere from 370 volts to 440 volts so please be careful around it and they are all different prices

  • dwkcool Jan 09, 2009

    yes I would put a start capasitor on an maybe a hard start kit but for sure a capasitor

×

  • Level 1:

    An expert who has achieved level 1.

  • Contributor
  • 1 Answer

I have a problem with getting my heat pump to come on. Sometimes it will be just fine and other times the green light on the thermostat will just keep blinking...and then at times it will finally come on and about 30secs later shut off without a temp change...Could this be my thermostat going bad??

Posted on Dec 13, 2009

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    President:

    An expert whose answer got voted for 500 times.

  • Master
  • 2,692 Answers

The pump (compressor) runs in the same direction all of the time. If it has a clicking sound and hum then the motor is not starting. It is then either the starter relay or more likely a start capasitor,if the unit has one .  I hope I have explained well. I also concure that the compreassor shoudl be running when the air handler is on .

Posted on Jan 08, 2009

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

There is a loud humming coming from outside unit, the fan is not rotating.


Your question does not include what type of system you are asking about, but the assumption is that it is a heat pump. The loud humming is the compressor running by itself while the fan is off.

This is the typical way a reasonably new heat pump operates:
There is a coil temperature sensor that initiates a defrost period to eliminate the frost/ice build up on the outdoor coil. In the defrost mode, the outdoor fan shuts off and the reversing valve in the heat pump reverses the direction of refrigerant flow to warm the outdoor coil. The same coil temperature sensor senses the temperature of the external surface of the coil and tells the defrost control when the frost is gone initiating another 'reverse cycle' to put it back into heating mode. In the heating mode, the outdoor fan runs again.

If you have the heat pump installed where snow drifts accumulate, you will have a problem extracting heat from the outdoor air, and coil frosting and freezing will be exaggerated. If you have excessive ice build up due to a defosting issue, the ice can actually stop the fan from rotating, but you would hear loud bangind and rattling for hours first as the fan blades come in contact with the ice.

If you do not have drifts, but continually have an excessive amount of ice build up, either the sensor is possibly faulty or the defrost control board is faulty. The sensor's clip could easily have been knocked loose from the coil by ice and is no longer sensing coil temperature and if so the result would be the lack of defrost initiation.

Feb 13, 2015 | Air Conditioners

1 Answer

Lennox elite heat pump throws cold air


The unit should give you an error code if something is wrong.

Here's the manual:
http://instalacionesindustriales.com.gt/pdf/Lennox_Minisplit_HE.pdf

Mar 25, 2014 | Lennox 7 Series MS7-HO-18P MS7-HI-18P Heat...

1 Answer

RTH3100C thermostat for an older Lennox heat pump


well the wire on x will go to e thr r is the red wire goes to r the wire on f willgo to g the y will go to y now the rest you'll have to verfy at air handler o will go to reversing valve common wire will go to c the electric heat will go to aux

Feb 06, 2014 | Honeywell RTH3100C - Digital Heat Pump...

1 Answer

Heat pump compressor wont come on in heat mode, works fine in cool mode, we get heat occaisionally for about 2 min, then the compressor shuts off. it is a fridgedaire window unit.


Try setting the thermostat at a normal heat setting. By raising the temperature too high the unit thinks that the heat pump won't be effective and go into strip heat mode.

Nov 17, 2013 | Frigidaire Energy Star Room Air...

1 Answer

My Lennox MS7 heat pump was installed about a year ago and hasn't had any problems until last week. It has started changing settings (like on or off, higher temperature, light on or off) without prompting...


Go to the unit locate the control module. Take wires to thermostat out. Now jump from R to Y your AC should come on. Jump R to W your heat should come on. Jump R to G your blower should come. If you have done these and it stay on or run as it should then you need a new THERMOSTAT.

Oct 26, 2013 | Lennox 7 Series MS7-HO-30P MS7-HI-30P Heat...

1 Answer

Lennox codes


e5: open or short circut of outdoor yemp. sensor or outdoor unit.

see more Air Conditioning Fault Codes

May 11, 2013 | Lennox 7 Series MS7-HO-09P MS7-HI-09P Heat...

1 Answer

What size dual capacitor does a Lennox 3 ton heat pump require for model #12HPB36-4P?


what is the ideal rating of capacitor for 3 tonner split type air conditioner, 220VAC?

Jun 12, 2010 | Air Conditioners

3 Answers

Lennox air conditioner is blowing hot air


Check your coils for ice, check your breaker and fuses for condensing unit, and is your condensing fan running? If not, you either have a bad fan motor or capicitor. After you hit the button, and wait for it to time out, (you should hear a click) take a butter knife, and spin the fan if it is not moving. If the fan start spinning by itself after your assistance, you have a bad capacitor

Jan 29, 2009 | Air Conditioners

1 Answer

My new Amana compressor Central Air-Heat Pump hums very loudly


When it hums, is it running? Or does it not run when it hums? I'm assuming it runs when you say you have to turn the therm off to get the noise off.. If it's humming and not running, you have big problemo friend..

Dec 02, 2008 | Amana PTH123B25AJ Heat Pump Air...

Not finding what you are looking for?
Air Conditioners Logo

Related Topics:

4,956 people viewed this question

Ask a Question

Usually answered in minutes!

Top Air Conditioners Experts

Dan Webster
Dan Webster

Level 3 Expert

8147 Answers

Bill Long

Level 3 Expert

577 Answers

Tim Whalen

Level 3 Expert

3056 Answers

Are you an Air Conditioner Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...