Source
r/hvacadvice•
Tesfallout

Pioneer Ductless System Troubleshooting Help Needed

I have installed 4 ductless systems at my house over the last few years and have had to overcome a handful of problems myself, but this one has me stumped. Generally, the issues are improper refrigerant levels or leaks that I've had to seal, but I don't believe that this is either.

The system in question is a brand new Pioneer 9k btu system and held vacuum without any issues. When I released the refrigerant into it, however, the unit simply did not cool inside. This unit does not have a high-side port, only a low-side port. While it was off, I hooked up my gauges to it and am seeing a static pressure that lines up exactly with my R410a chart. When the system is turned on, the compressor kicks on and the low-side pressure falls to near zero numbers. I have inspected my lines for kinks and twists and I believe that everything is fine, so the question is, what else could it be?

I have had to learn all of this myself because money, so please let me know if I'm missing something obvious here.

Posted Jun 27, 2022, 1:22 AM UTC

15
JudgmentMajestic2671Unverified •

Sounds like there is a blockage somewhere.

2
Urnipt_TtackaApproved Technician•

Checking the charge with the system off will tell you almost nothing, checking the refrigerant charge on a ductless without reclaiming and weighing it will tell you exactly nothing.

1
TesfalloutOP•

I probably should have mentioned this above. As part of the troubleshooting we did indeed reclaim and weigh the amount being put into the system with the same exact symptoms.

1
Urnipt_TtackaApproved Technician•

This might sound like a dumb question but are you sure the valves are open?

Sounds like you've got a restriction, if it's not the valves then I'd be looking at the EXV.

2
TesfalloutOP•

Yeah, I have double and triple checked the valves. I'll see if I can find time to take a look at that and will post with some updates.

1