Heating Issue with a Heat pump in heat mode.

[toyo066]

Working on an r22 pos eco temp in cooling mode high side 198 low side 62 its about 75 inside. Switch it to heat mode and the common port drops to 6 psi cap tubes freeze up. 3/4 side goes to 165 and the 3/8 goes to 21. freezes up from service valve to the tips of the cap tubes. Took it apart flushed the system, checked the piston (No TXV) blew nitrogen through it as well as hit the service port with rx-11, change the biflow filter, vac system back down re charged it in cool mode and again it is back to the same crap. Note: I have thought of everything on this inside coil is clean the fan motors run good no problem with the line set. The only thing that I can now think of is that I should change the the txv in the ahu thinking that check valve is clogged. However, that is why I am on here right now trying to get some feedback........ This is the crap I love, dec 25th service call rom hell.

[ryan1088]

Did you weigh the charge back in after you had it open?

[toyo066]

yes and this is what I am getting...... I have done everything correct... Been in this field for 12 years so all the things that were suppose to be done was done correctly. That is why I also put down in the cool mode the pressures were 198 h and 62 on the low and temp is 75 inside.... I think that should be right on an R-22 in cooling..... The bottom should not fall out like that even if I was low by 2 pounds hell, I may even go as far as saying 3 pounds low.

[SBKold]

Im not sure what manufacturer Eco temp is but is it like carrier where piston is in ll service valve?

Did you lay eyes on indoor metering device ? Was it changed or anything recent?

I would recommend throwing a piercing valve on the liquid line close to ah to verify that is the culprit of pressure drop.

[toyo066]

Eco Temp is ICP Carrier product.... CHEAP one.... IT has a TXV Lennox ahu and I changed it out when the condenser was installed. Mechanical device so no braising was needed. Could be bad check valve and the only reason why I am thinking that is that I do have pressure going in but it drops like hell coming out. I was thinking of doing that today with the piercing valve but the more I thought about it is that if my pressure drops like that at the service valve it has to the the check valve...So tmw it is going to be another 56j20 txv going in... Cant think of anything else.....

[SBKold]

Ok that's what I was getting at. You are not reading liquid pressure at that port. It is after the metering device so that's low side upstream of distributor.

So we still don't know what the liquid pressure is.

Are you 100% sure the indoor valve is not a cooling only one with no check?

[toyo066]

I have to check it out tmw. The liquid pressure in this case is 164 going into the system the gas coming out of the ahu drops to 21 at the condenser service valve... So that is why I am saying that it has to be stopping in the ahu and dropping there. If you think about how it flows, to me that is where it is at. The more I talk about it I am leaning more on that. I guess that is why its good to go over it on a fresh mind. Plus not to say I was not a happy camper out on christmas day away from the fam...

[Firebird A/C]

Sounds maybe like the reversing valve is not shifting all the way over on the heating mode. Does it sound like the reversing valve is switching? Is the common suction port after the reversing valve or before reversing valve?

Also could be plugged outdoor cap tubes. That is why it is icing up. If so, time for a new outdoor unit.

[SBKold]

I have been in your shoes so many times out there frustrated on the job and not thinking straight. I could have easily been there too. I'm surprised anyone called you out on Christmas day though.

I will stop leave or even just take a short break like you are now and will get a new plan of attack for tommorrow. Many times I would come here to make a post and just by sitting down and typing out all the descriptions I will answer my own questions. This website is such a powerful tool to be able to brainstorm.

What I'm trying to tell you though is on icp uniits where liquid line valve is also piston assembly --- if you stick your guage on its after the piston. - low side

You may also see frost after valve in colder outdoor temps just like other units but you cant see it so easy.

[jledford382]

I had a Carrier last week that was doing this same thing. The reversing valve was sticking and not shifting all the way over. After a good whack, it shifted. Customer wanted to see if it would work ok after that and I haven't heard back from him......yet.

[toyo066]

sounds like the reversing valve is working I did wack it a few times but it does sound like it is working... Cap tubes I am leaning on that too but right now after going over and over it sounds like check valve..... but I am not 100 percent sure.... After speaking with a friend who has been in the industry for 20 years he seems to think check valve.....I will post it when it is done....

[toyo066]

Yeah so am I but its a rental prop and this guy is a real jerk. I mean it is not even that cold out like today it is 68 and he wants his landlord to pay for a stay in the hotel for over night. It freezes up like 10 seconds after it is on and I removed that piston and checked it very throughly blew it out real good with nitrogen so today I am hitting it with the 56j20 and go from there. I am pretty sure the check valve goes through it. Here in Jax we have alot of lennox and Goodmans and I hate both of them with a passion, you can blame the systems all day long but if you have one thing wrong with them forget it.. I have sold both lennox and goodman for a few years and have swicthed from them to Trane and Carrier products....

[garyed]

Is there a 3/8" flare fitting that connects the liquid line to the condenser? If not then don't bother reading on. If so then that is where the metering device is in heating & most likely stopped up. Before changing anything else I would check that piston in there first.

[toyo066]

yes there is a flare and there is a perfectly good piston in it please read the first one where it states that I did take the piston out and flushed the entire system out with nitrogen. I checked everything and after changing the txv indoor one due to a check valve it still did not work..... No check valve on it...... but now it has me going crazy, cap tubes or rev valve ..... what the hell I have never ran into something like this it has me stumped and I usually dont get stumped on much....

[SBKold]

Can you blow through the valve with no restriction ?

[socotech]

Did you check the screen at piston in condenser?

[Firebird A/C]

In heating mode can you check the suction pressure after the reversing valve???? Meaning is there a suction port between the compressor and the reversing valve? That will help you with telling you what is going on with the reversing valve.

[SBKold]

You might just be low on gas.

[air1]

I had a similar problem a few years back. Several techs before me tried everything and still could not correct the problem. I put my gauges on and immediately could see there was a restriction. Guys before me pulled the piston and checked it and it appeared fine. I pulled the piston and it wasn't plugged but the orifice looked too small for the size piston. I pulled out my handy drill index to check the piston and sure enough the orifice was too small. It was the correct piston but somehow copper had deposited itself in the piston orifice. I used my drill and chipped out the copper and put the piston back in and it worked great after that.
You really need to measure the piston orifice to make sure copper hasn't reduced the orifice size through some type of electrolysis. You'll need a drill index that measures orifice sizes.

[garyed]

Before I did any more to the system I would throw anther pound or two of gas first to see what things looked like. The only reason we hesitate to to throw gas at a system now is because of the cost but it's always a quick and easy way to test a suspected restriction.
If the outdoor piston looks O.K. then it could also be the screen right before it. On Carriers that piece of 3/8" tube with the flared end that connects to the condenser usually has a screen built in to it. The fact that your pressures were O.K. in the other direction makes that idea less likely but it still is a possibility worth checking.