If TXV ( indoor section ) is not opening in cool mode wouldn’t that be the same as closing off the LLSV. Thinking you just need to make sure RV is always energized and never deenergize while pumping it down in cool. If it has a LPC, may need to jump out, as that will drop out RV and shut system down. Also who’s to say your going to get the total charge in the outdoor unit especially if your lineset is on the longer side. Don’t believe your suppose to pull into a very low suction pressure with a scroll compressor also, unlike a recipercating compressor.

Is the indoor TXV adjustable? Yea maybe unable to pump down if the TXV is a hard shut off during cool? I always thought you still get a little seepage no matter what?

 

Sorry Bazooka, but i think he's referring to the outdoor TXV, and no is the answer you'll have to recover

 

Sorry Bazooka, but i think he's referring to the outdoor TXV,

Yes! That’s certainly could be true, thinking I was to far into the forest to see the trees on that one.

 

I have pumped up a heat pump to hold the charge in the evaporator coil before. Might not hold it all.

 

if no charge was added due to extra long line set, then it should hold it all

 

Put in cool, close liquid line valve, bleed through gauges. Should not be that much refrigerant in line if they are not that long, or close off valves and recover line set. I'm guessing
you are talking about the indoor coil.

 

You can pump it down in either heat or cool mode.
Just be certain to close the right valve

 

lol, im sorry but that is a funny question....just do the pump down as far as you can go and recover the minor amount left over..

 

I think it best to recover it all and weigh in the whole charge on a heat pump. Again I think he's talkin about the outdoor TXV. Why save PART of it and have to extrapulate the rest? new unit there should be an allowance for you to cover the cost associated, drier, r410a,etc. labor allowance as they're called are never ment to "pay you" only help you recover some of your expenses. Or just see if you can get another unit, your client would feel better about that.
I see why he wishes to "save" the charge, HP could have 14-16 lbs iin it.

 

I’m willing to bet they welded the copper without flowing nitrogen...all that ash trash is floating around inside...seen it too many times...
I always recover with a catch all filter dryer and then reinstall the refrigerant with it on..

 

my $$$ is on the sensing bulb is broken off

 

One word of warning here. You need to make sure that the valve will hold pressure backwards when pumping down in heating. Trane had a ball valve on the gas line that would hold pressure in the condenser but when trying to pump down in heating it would not hold the pressure and push the ball out of the socket so you could not turn the valve to open it either.

 

Some a/c scrolls will not go below 20 psig. on a pump down.
The last two were that way for me.

 

You should weigh the charge anyway might as well
recover
Weigh
Change valve
Change drier

Now you’ll know!

 

Pumping a HP down in heat mode is virtually the same procedure as in cool made. You close the liquid line port off & when you think its pumped down enough you close the big line port. The biggest difference is you usually can't get all the gas out like you can when pumping down in cooling but you can get most of it. You probably need to bypass a pressure switch too. Sometimes it's not worth the hassle if you still have to recover what's left in the condenser or if you want to put a dryer outside the unit too.

 

a question, do you have recovery machine? would be better recovery the refrigerant in my opinion.

 

@ Garyed

Do I mis understand? If in AC its close, liquid first then suction when satisfied, in heat pump mode wouldnt you do the opposite for heat pump? Shut gas side first then shut liquid line last since its in the reversed flow / state of AC?

 

@ Garyed

Do I mis understand? If in AC its close, liquid first then suction when satisfied, in heat pump mode wouldnt you do the opposite for heat pump? Shut gas side first then shut liquid line last since it’s in the reversed flow / state of AC?

After 3 years

 

If you want the refrigerant to be in the indoor coil you would close off the liquid line to back it up in said coil.

 

Apparently

 

Apparently

 

My question.... for whatever reason...I've never attempted to pump down a heat pump to the condenser in heat mode. I always energize RV (except Rheem and ruud) and pump down that way.

I thought I was understanding that some of you do a pumpdown to condenser without energizing the RV and leaving it in heat pump mode.

 

you see when the pressure goes down to nearly 0 on the suction line, that the refrigerant has been "sucked in"

 

Seve the headache and just recover the refrigerant.