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A-1 Tech, Service Manager
Category: HVAC
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Experience:  I have been in the HVAC business for over 40 years.
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my carrier air conditioner (heat pump) will not run.i put it

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my carrier air conditioner (heat pump) will not run.i put it on but compressor outside just clicks
Hello there and welcome to Just Answer. My name is XXXXX XXXXX I will be assisting you today. I am an engineer with over 30 years of electrical and electronic training, repair and installation experience. I will try and answer your question accurately and precisely so that we can get you on your way.

You most likely need to change out the starting capacitor. If you look in your heat pump's junction box you will see a large silver 'can'. It may be bulging. On the side of it will be the rating of the capacitor in Farads and Volts for example 40uF 440V AC.

Go to your local HVAC supply house and you should be able to buy one for under $20.

Kill power to the unit - there should be a disconnect switch or fuse in a box close by. Replace the capacitor and you should be good to go. Let me know if that doesn't work. I'll be here.

If you are uneasy about doing this, a local HVAC tech should be able to do this for you for $75-$100 parts and labor.

I'll be here if you need further help with this issue. Please let me know.

Customer: replied 3 years ago.

so the capacitor will be in the conpressor box outside or the one in the attic.i just had a problem with my air compressor in the garage it was the starting capacitor.also there is a box of small glass fuses on the unit in the attic,i am a new owner of the place

The capacitor is on the actual condensing unit outside. There will be a small box that houses a circuit board, contactor and the capacitor.

I'll be here if you're still stuck.

Customer: replied 3 years ago.

Ok I will get back to you tomorrow when I change it thanks

Sounds good.

Don't forget to kill power to the unit.

Customer: replied 3 years ago.


What push button is this? The push button on the contactor?

Please let me know so that we can continue.


Customer: replied 3 years ago.

the push button next to the capacitor .there is 427-a in there an it is low can we put in 410-a in its place.will it match up it seems to have a leak in the sharder valve,having trouble finding 427-a

Ok, I'm not quite following your dialog. I am going to opt out of this question which will allow other experts to chime in.

Hold on.

Hello, my name is XXXXX XXXXX I will assist you today

R 427A is a drop in replacement for R-22. You can"t replace it with R 410A

You will need to either add R-427A to system or remove all the R427A and go back with a different drop in replacement or put R-22 back in the unit.
Customer: replied 3 years ago.

do i need to flush out the system or just drain out the 427 oil anthen put in 410.or should i just try to get 427-a

You can NOT convert this unit to R-410A.
You can simply remove the R-427A and put any other drop in replacement or go back to R-22. There are many drop in replacements that do nor require you do anything with the oil.
Customer: replied 3 years ago.

great which one can i get beside 427-a is there another one i can use that i can find easier

Please allow me a few minutes and I will get you some replacements.
Customer: replied 3 years ago.

thank you

ISCEON® MO99™ refrigerant
The Quick Switch for R-22 Replacement
Customer: replied 3 years ago.

ok i will look for that stuff asn get right back to you.thank you

Thank you, XXXXX XXXXX is by Dupont and should be available.
Customer: replied 3 years ago.

i found 427-a ,i am picking it up now i don,t need any special gauges for thos gas do i my ac guy is worried about that

No, no special gauges are needed. A pressure temperature chart from supplier would be helpful as pressures will be a little different from R-22.
A positive rating is greatly appreciated if you are satisfied with my service. I will be available for follow up if needed.

Thank you,

Customer: replied 3 years ago.

ok oner last question i put in 417-a got pressure at 75 low side 200 high but it come out at 68 degrees from the vents should it be lower,an what can i do to make it more efficient

The air out the vents should be 17-20 degrees lower than the room temperature, or the air temperature entering the filter.


Are you using R-417 or R-427?


Customer: replied 3 years ago.

427-a the house temp is 84 the vent temp 68

Then you are really close on the charge, you have a 16 deg. drop
You may need to add just a little more refrigerant. Is the suction line sweating any?
Do you know the suction line temperature?
Customer: replied 3 years ago.

it is cool but not sweating i will add a little more 427a

Customer: replied 3 years ago.

it is not sweating just cold but with air on the temp is climbing during the day when i got there at 12 it was 79 inside then it climbed to 82 by 5 with the ac running


Did you try adding refrigerant? What is the low side pressure and the suction line temperature? I will be out for a while, possibly we can continue this in the morning.


Customer: replied 3 years ago.

the low side is 75 the high side is problem now to me seems to be when it comes oput of the ducts it is only 69 degrees,back home in new jersey my air comes out of the ducts at 59 degrees during the day an 56 in the evening.the best i get here in savannah is 69.even in the evening

If we get the 17-20 degrees difference as stated above, we are good. Higher efficiency units tend to have a lower temperature drop. 18-19 deg is optimal.

What is the temperature drop after the house cooled down?
What are your pressures now running? High side and low side?
What is the suction line temperature?
Do you know what type metering device you have? Expansion valve or piston?
Please verify to me the refrigerant we are using. R-427A?
We really need to know these things and we can proceed.
Customer: replied 3 years ago.

i will check the temp drop at difference time of the day,an the pressures at different time of the day,an i will look up what kind of metering device ,it is 427-a i put in .i do not no how to check the suction line you need to no what my system is unit in attic is 18 years old unit outside is 3.i will get back to you tonight


Thank you, XXXXX XXXXX sorry for all this trouble, but we really need to know these things to get it right. If you can put a thermometer under the insulation outside and then tape it down to the copper line would be great for getting that temperature.

Depending on metering device, we will be either checking sub cooling or super heat. I can explain later.

Thank you,

Customer: replied 3 years ago.

ok i will get a thermometer an check the temp,also i think it has a real slow leak

Thank you
Customer: replied 3 years ago.

well i put more freon in it come out of the vents around 59 degrees but the low pressuere is 90

We need to be sure the compressor isn't flooding back. Is the suction line sweating? What is the suction line temperature?
What did the discharge pressure do?
Customer: replied 3 years ago.

okay i will rate you today i open up the evaporator an it was loaded up with alot of debri an what is the best way to clean the fins .the suction line is sweating. i cleaned the evaporsator a little the temp is coming out of duct at 59 degrees,so hopefully when i clean it ,it will get even better. an i got low side 80 hi side 210

You can brush the face of the coil to get the heavy stuff built up. Then you can purchase pressurized cans of evaporator coil cleaner to help with the dirt build up inside the coil. You should be able to shine a light through the coil and see the light on the opposite side. Sometimes you can't get one clean in place and the coil has to be removed, taken outside and flushed out good with water hose. Be sure to tape up refrigerant lines if you remove the coil to keep water out of the coil.

Once the coil is cleaned, the refrigerant pressures will actually rise. You may need to adjust refrigerant accordingly. This will also help with the suction line temperature being too cold.

A-1 Tech, Service Manager
Category: HVAC
Satisfied Customers: 526
Experience: I have been in the HVAC business for over 40 years.
A-1 Tech and 2 other HVAC Specialists are ready to help you

Thank you for the positive rating. The link above shows a cleaner you can use and should be able to get locally. If I can assist you further, please let me know.


Thanks again, Ron