Refrigerant Lines for Heat Pump

I've got a fairly new Heat Pump that appears to have been installed in a questionable fashion.

The Heat Pump was installed in an attic to replace an older central air unit and also provide a supplemental heat source when Propane costs went crazy a few years ago. The unit works well when it works, but after quite a few problems over the years, it just didnt seem right for a new unit, so I decided to have another company provide PM service and determine if these recurring problems could be fixed.

The initial evaluation pointed to a number of installation shortcuts and mistakes, and the cost of remediation exceeded the cost of the heat pump itself, so I decided to get a third opinion. The third opinion conflicted with the second in a number of ways, but there was agreement that the life of the equipment would be affected by the way the installer handled the refrigerant lines.

Specifically, instead of running new refrigerant lines, the contractor who installed it used the old line from the AC and created a connection to the wider size required by the Heat Pump. Due to the location of the unit and the layout of the home, it appears that the cost to rerun the lines is an unknown and a time/material job for a 2 man crew that could be quite expensive (up to $ just for the lines). In a discussion with the HVAC pro who is now maintaining the unit, we came to a mutual conclusion that it would be best to save the money on the lines toward maintaining and eventually replacing the unit.

My question is whether there are HVAC pros that specialize in this type of thing and might be more affordable. I am happy with the company as far as servicing the equipment is concerned - they are responsive and quite competent in that area. But, when they said the job would be a "pain in the butt", the thought occurred to me that another contractor might not view it that way.

Any input and advice will be greatly appreciated.

it all depends on the layout of your house, and the lineset requirements.

how much difference in size is there? there's nothing wrong with using existing lines if they are not too restrictive, and they are not leaking...

What size unit, and what size is the line set. There may be nothing wrong with the size of the lines.

I am not certain, because the exact sizes were spoken to me but not written on repair estimates. What I do know is that the original lines were smaller than the line required by the heat pump. The original ac unit was a small Rheem AC unit, and the replacement heat pump was a York 2.5 ton system, Model # E1RE048S06G . The point was made that the lines were restrictive which was determined by a measurement that was taken as the unit ran - the load the unit was under was apparently higher than it should have been. I am a laymen here, but two techs reported this same issue.

There have been problems with leaky lines over time, but this last 18 months there was no leakage. Hope that helps.

I answered this in part below. I have yet to have the Winter PM where the Heat Pump is checked, but as of Spring, the units had gone 18 months with no refrigerant loss. Up to that point, replacing refirigerant was a regular part of PM's until I switched contractors.

That model number is a 4 ton unit not 2.5

Probably 1/4" liquid line

thats what i was thinking