Background....

System outside is a Carrier 2.5 Ton recip compressor about 6 years old. The coil Inside WAS a very old Honeywell 2.0 Ton slab type .
**Yeah I know, mismatch in compressor and coil size. ... that is why it was fixed.

So, the old coil had a leak, so the techs installed a new Trane 2.5 ton "A" coil with TXV in it's place. VERY noticeable difference in cooling capacity.

But then, about an hour after they left, the compressor kicked off and would not come back on. The condensor fan and air handler fans both kep running running.

Called the contractor about it. He said they needed to come back an install a "hard start kit" to the compressor.

When I called he didn't even hesitate as to that being what was wrong.

Says it was because of new "A" coil was so much more efficient, but connected to a 6 yr old 12 SEER comp/cond unit, because of a TXV on the new coil, that was the reason I needed this so-called hard start coil.
They also took off the dryer/filter on the suction side and put a similar looking one on the liquid line. Not sure why?

Can someone explain why I needed this device added? Actually it says on the side of this thing, "Super Boost". It was connected in parallel to the capacitor. What does this thing do and why do I need it?

Last time this happened, before the coil replacement the service guy added some R-22 freon and went on his way. Now with new coil, they assure me the pressures are 100% right on the money, but something about this TXV thing.

Comments appreciated.