Air Conditioning - Coil Restriction

I'm being told, after the 4th service call, that I have a restriction in the coils and therefore need a new coil...

I don't know how to tell if this is the solution and it is an expensive option!!

Problem is that the system cools for about 20 minutes and then blows air that is only slightly cold.

I put in a new condenser, new expansion valve....Please advise!

It is very possible, can't see from here. My biggest concern is why did they change the condensing unit? A resrticted inside coil would not give the impression that the outside condensing unit is bad.

Because it was old and they thought that it was the problem.

How do they test for a restriction and how do they know it is a restriction and not a leak??

Is it fixable or is the only solution a new coil??

Thank you for you help!!

The first thing you need to do is find a new contractor, call or contact York through the internet and find a local York dealer.

Are you seeing ice build up on the copper lines going to the indoor coil thats on top of your furnace ?

No, but I will run it this morning and check again.

No ice....no restriction????

I assume we are talking about the evaporator coil. How is it restricted? Is the refrigerant flow restricted or the air flow?

Did they put new filter driers in with the new condenser? Did they remove the old driers?

Perhaps the restriction (if that's what it is) killed the old compressor.

How old is the old coil? do you know the brand?

It is a York and it was installed in 97. I don't know how it is restricted. The service guy is coming today and I am trying to understand how this all works!

Thanks for your help!!

No ice....no restriction????


It would be an indication of a possable restriction

How do you test for a restriction....is it something they can show me??

You would be able to tell there is a restriction somewhere in the refrigerant circuit with ref gauges.

I still think you need to find a qualified York factory authorized contractor and or a York factory tech........its not that hard to do, just call York.

I'm being told, after the 4th service call, that I have a restriction in the coils and therefore need a new coil...

I don't know how to tell if this is the solution and it is an expensive option!!

Problem is that the system cools for about 20 minutes and then blows air that is only slightly cold.

I put in a new condenser, new expansion valve....Please advise!
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It seems it has enough moisture in the refrigerant system, over time, to freeze off the flow.

The tech would have to have checked the temp difference of each circuit in the evaporator coil to determine one of them was restricted. He must confirm with a demonstrated test that the E-Coil gets restricted!
It's possible; but I doubt that the cooling coil needs changing!

Does the airflow stay the same?

A restriction in the liquid line or at the evaporator metering device will result in: low suction pres; high superheat; usually high head pres; high sub cooling; low amp draw.

Many times U can feel the temp change or see frost on the line.

A suction line restriction up-stream 'between service port & cooling coil: low suction pres; high Superheat; low head pres; norm to high sub-cooling; low amp draw.

A suction line restriction down-stream 'between service port & compressor (screen): norm to high suction pres; high Superheat; low head pres; norm to high sub cooling; low amp draw.

If there is a liquid line filter-dryer upstream inside the condenser from the liquid line service port: Low head pressure; low amp draw; system simply pumps down as though the liquid line service valve were nearly completely closed!