First mini split problem creep up.

[428PI]

Was running the mini split in ac mode last night and the one in the bedroom froze up. It's a Pioneer 27k with 9k unit in bedroom and 18k in other part of house. Was running them around 68 degrees. It was I thought a little damp and warm in the house (above 72) so decided to turn them on. The one in bedroom froze up this morning and I heard a noise like dripping. Shut unit off and sure enough, the coil is froze up and dripping onto floor. The one in other part of house is just fine. Drains ok. Ran it in heat mode all winter and just a few days ago. Works fine. It sounds like it might be low on freon (according to quick things to check) or did I just hit the right humidity and outside temps (got perhaps around 50 outside last night). Checked the filters and bedroom is clean but other one a little dirty. I'll wait and see if it does it again in a few weeks (going to be cool here for a week or so).

 

[Kaizen]

its not just the filter that you can easily clean but the internals. Recommended yearly to clean i believe. Its not an easy thing. Some things on market to make it easier. Also make sure outside unit is cleaned. easier then heads.

 

[jjrbus]

My go to for mini issues is shutting off the breaker for a few minutes. A min is more computer than anything else, so a reboot is in order. Does sound more like low refrigerant, but I am reboot expert, not a tech.

 

[428PI]

I hooked up gauge and only running 75 psi on low side. Bought me a 25 lb R410a cylinder today. Will be putting some in to bring pressure up to 115 or so when it warms up. Cooled off today and it's running fine in heat mode.

 

[ratflinger]

I hooked up gauge and only running 75 psi on low side. Bought me a 25 lb R410a cylinder today. Will be putting some in to bring pressure up to 115 or so when it warms up. Cooled off today and it's running fine in heat mode.

How much did that cost?

 

[428PI]

cost

240 for 23 lb vs 130 for 2lb cylinder from some sellers.

 

[428PI]

Ran into another problem this morning. Noticed a slight discoloration on wall thinking it was moisture. Pulled back inside wall unit and found gooey mess. The asphalt tape I thought would work good to seal moisture doesn't hold up to heat. Totally filled the foam around lines with absolute mess. Used press and seal wrap to protect wall. Thinking that's where my leak but couldn't detect any. Thank God for brake clean, gloves and fast orange. Now what do I replace foam with?

 

[428PI]

Got to 60 yesterday so charged the system. Started off at 70psi or so on gauge. Added a pound and got to 80psi or so and frost on evap disappeared. I ended up putting a little under 3 lb in it and got pressure up to 110psi. The manual does warn about if it's more than 15 percent low that one should evacuate and recharge since it might have disrupted the gas ratio. I thought I would quit at pressure as the temp pressure chart started at 65 to 70 degrees outside temp at 115 psi or so. So I lost (or never had) roughly half the refrig. in one year. I suspect the big inside unit that had the melted asphalt insulation is the culprit but never saw any leaks with the gas leak detector fluid (does it get old?) or my electronic detector only detected the gas leak fluid so useless. I put foam insulation over the inside line flares. I may peel them back in a few months to inspect to see if any oil is soaking into insulation. I think I mentioned it but the inside big unit didn't have any pressure on it from the factory so could be the evap in it but really just think it wasn't handled properly on the pressure and rubber plug from the factory. I didn't want the hassle of sending it back and getting another one as it was on backorder when I installed it.

 

[racecougar]

Noticed the white insulation (PE) on your line set. Have you inspected the line set for signs of oxidation? That insulation is known to be acidic and react with the copper line set if any moisture makes its way in. There are a bunch of threads and videos on this topic on other sites. It's a likely culprit for your lost charge.

 

[428PI]

There are a bunch of threads and videos on this topic on other sites. It's a likely culprit for your lost charge.

Haven't noticed anything yet. I will keep an eye on the indoor unit that melted the asphalt insulation. I covered the piping there with soft foam pipe insulation. I'll peel it back in a few months and inspect it and keep an eye on the evaporators and see if they start to get ice formed on them indicating low freon level.

 

[jjrbus]

Spent some time looking for leaks with soap and water and cheap electronic detector. Techs do not like to look for leaks! Tried one of the high tech bubble fluids, nothing. Bought a Accu Trac hypersonic leak detector, found leak in a few minutes. Minute leaks inside evaporator coil, unlikely I would have ever found it with bubble juice. Even with cost of detector cheaper than having tech do a gas and go or 2 and then look for leak.