No clogg what so ever in the refrigerant lines will result in high head pressure. That is a very common misconception... based on the idea that if the refrigerant flow is restricted, refrigerant GAS will back up into the condenser coil and cause the high head pressure.
However, in the condenser coil the hot gas is *condensed* into a liquid, the volume then shrinks and the head pressure actually *drops*
There is one fairly rare exception... that is when the condenser is a *micro channel* type instead of a tube and fin type.
Here is a video on the topic... tell me if you have a micro channel type coil or not.
Watch this video above first. Micro channel use has since been discontinued by a number of system manufacturers.
In that case, your tech has about a 20% chance of being correct. (that is a 1 in 5 chance) in his view that there is a restriction in the refrigerant liquid line.
You can tell by inspecting the condenser on your unit if it is micro channel or not... if it is not micro channel, then your tech in this case is a little short on training and experience and he or someone before him has over charged your system with refrigerant.
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