Heating, Air Conditioning, Fridge, HVAC/AC not cooling enough

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Hi, really looking for advice here. Any help is much appreciated. I will put as much information as i can.

House is 2200 sq ft built 10 years ago.
Rheem/Rudd furnace and AC. about 10 years old
new 1/3 hp furnace motor wired at high.

AC always worked fine until this year. In June, AC was not cooling. Service technician found clogged furnace filter and dirty coil. Freon on the low side but within spec. Cleaned it all and worked fine until 2-3 days ago.

Temperatures here are now around 100 F. Coil and big line started to freeze up. I noticed because 1) the temperature inside the house was creeping up and almost no air was felt at the floor registers. Here is what i did:

1. cleaned furnace filter
2. cleaned A coil
3. cleaned outside intake vent
4. clean air exchanger filter
5. ensured condensation/water pump was working
6. cleaned outside ac unit fins
7. Ensured power was going to ac unit and fan/compressor were working

It has been two days. i let the coil thaw and still can't cool the house. Usually i can get it down to 70F without a problem. Now barely 78F and it just stays there. What can i do to resolve this? What could i test?

Some notes:
AC runs continuously
ac fan runs. Does not cycle on or off
Some condensation on large line outside and i can feel coolness
AC compressor is hot to the touch and i can hear it humming
small line inside at coil is warm/hot to the touch
large line inside at coil is cool but not cold. No ice.

If i reset the breaker, the large line gets cold immediately then warms up a bit.

Answer
Stephane,

You should be getting somewhere around 20 degree temperature difference from the supply register ( closet to the fan section ) and return. Your larger insulated line should not frost but should be sweating and cool to the touch all the way back to the outdoor unit. If your indoor coil only is icing and your not getting around 20 degree temperature drop across indoor coil and the larger line is not cool to the touch and sweating at the outdoor unit or to the compressor you may have a refrigerant leak. You did not mention if the tech. just add refrigerant or actually found a leak and made repairs. Also how long ago did he come out to service unit initially, early summer?  Make sure all your supply registers are open also. When you replaced the blower motor did you increase the fan speed ? , was the old motor on high also? Reason I ask is the 20 degree split may be less if the blower fan is on high compared to medium. What does clean outside air intake vent mean? You bringing in some OD air into your return duct?

Heating, Air Conditioning, Fridge, HVAC

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40+ years diversified experience.An HVAC/Refrigeration Self Employed Contractor since 1986. NATE Certifield. Answer questions pertaining to Residential and Commercial Air Conditioning , Warm Air Heating, Heat Pump systems.Mechanical and Electrical troubleshooting of these systems.Be as detailed as possible when describing problem.Packaged unit or split systems.No appliance questions.

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Installation and Troubleshooting, Mechanical and Electrical, in following areas, Refrigeration ( Walk In and Reach In Coolers and Freezers ) Commercial Roof Top and Packaged Heating/Cooling ( Natural Gas,Propane, Electric, and Heat Pumps ) Computer Room Air Conditoning Systems,Commercial Residential Packaged and Split Systems Air Conditoning and Heat Pumps.Warm Air Oil , Natural and Propane Gas Heating systems.

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Graduated from Private Technical School in 1975. An HVAC/Refrigeration Contractor . Have Unlimited Heating/Piping and Cooling Contractor License.Limited Sheetmetal Contractors License.NATE Certifield. York Certifield Master Heat Pump Technician 1986. Served 33 years combination Active Duty Air Force , Air Force Reserves and Air National Guard in the HVAC/Refrigeration Shop/Mechanical Shop. Troubleshooting/Installing HVAC/Refrigeration Equiptment Worldwide. Retiring in 2003 as a Senior NCO ,and a Mechanical Superintendent.

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