installers overcharging txv systems

[hurtinhvac]

Here's what I have been finding. I keep getting sent back on our installers new installs. When I get there I keep finding overcharged units. Its usually 90 inside and 90-100 outside when they are setting these units. They say they are charging them to 10 degrees subcooling. When I go back the indoor temp is usually 70-80 depending on the person. The outdoor temp is still 90-100. My subcooling is extremely high around 40-50 degrees. I always remove refrigerant to reach 10 degrees subcooling. What is going on here and how can I help them stop overcharging these units?

If they are sincerely trying, they are probably not letting it run long enough before adding and in between shots. The liquid line temp that appears not to be dropping in response to adding Puron can suddenly take a dive quickly if the system is allowed to run long enough.

I usually start cleaning and do pretty work while letting a new install cook for a half an hour, give it a shot and go back to clean up, putting away tanks and tools and loading up the old equipment - coming back periodically to check and give it another shot if needed.

[hvacmike85]

If they are sincerely trying, they are probably not letting it run long enough before adding and in between shots. The liquid line temp that appears not to be dropping in response to adding Puron can suddenly take a dive quickly if the system is allowed to run long enough.

I usually start cleaning and do pretty work while letting a new install cook for a half an hour, give it a shot and go back to clean up, putting away tanks and tools and loading up the old equipment - coming back periodically to check and give it another shot if needed.

it can't run too long before checking charge on new exp

[sparky05]

1 deg says it wasnt your filter dryer, but the txv, and I always do the dryer exp when theres a problem, manf says change dryer when system is opened for any reason but some people just dont wanna pay for a 20$ dryer, some H/O are just smarter than us I guess, anymore I just include it in the pric3 and dont tell em cause it will just raise questions

Not according to the Manufacturers Technical Rep, They came out to see how a unit could have a negative S/C, after checking through the system with me he determined it was probably a clogged up filter dryer, the recommendation to change the TXV was so we would not have to pump down the system again to change it if there were other problems.

[Pete954]

Had this same problem numerous times 4 summers ago and that's how we solved it. Braze and leakcheck first so you can pull your vacuum while doing everything else. That way it can run for a good while before making any adjustments. Also turned out we getting trigger happy since 410 takes longer to register an adjustment.