Heat Pump confusion

[chrisevansac]

I've got a goodman doing the same thing. Except in both heating and cooling. Eager to see what you find

[philjafo]

Was the charge weighed in at install? Once we started weighing the charge in at install the callbacks stopped, 410a is two different refrigerants and will lie to your guages for the first few hrs of runtime. You may also have a leak, hard to tell without the proper diagnostic tools.

[beenthere]

Once we started weighing the charge in at install the callbacks stopped, 410a is two different refrigerants and will lie to your guages for the first few hrs of runtime.

Haven't seen it "lie"/mislead my gauges yet. If that were true, you won't be able to check the charge on any unit after you recharged or added charge to after you replaced a leaking evap coil.

[codgy]

agree that weighing charge is the best option. never a callback.

[beenthere]

agree that weighing charge is the best option. never a callback.

Weighing in is best. But R410A doesn't "Lie" to your gauges for the first few hours.

[philjafo]

Not trying to start an argument beenthere, it was just the easiest way to put what I was trying to say. When a 410 a unit fixed orifice is installed and charged according to sh, it will be correct and something happens to the refrigerant that changes the pressures and temperatures. Weighing the charge according to the manufacturer specs eliminates that problem.

[rglasgow]

The refrigerant does not change. Maybe your indoor conditions change.

[kls-ccc]

I have to agree, 410 can be touchier on charging. Last summer I had a trane with EEV, new system start up. Let it run 15-20min to stablize, both SC & SH were off, LIke 3SC, 35 SH. Added and waited, press, SC & SH got closer but still off, added more, waited, better but still not right. Houra & 45 min later we looked good. Left the job a little after 5 PM. got a call around 9PM no cooling. Went back out, grossly overcharged. Adjusted it down into a recovery tank to where it would run and told them I would come back the next moring to finish adjusting. Had that happen to one of my techs also.

[beenthere]

Not trying to start an argument beenthere, it was just the easiest way to put what I was trying to say. When a 410 a unit fixed orifice is installed and charged according to sh, it will be correct and something happens to the refrigerant that changes the pressures and temperatures. Weighing the charge according to the manufacturer specs eliminates that problem.

You or the other techs were you work are doing something wrong then.

By what your saying. We can't go and find that a schrader was leaking, replace and and then top off charge by SH.

Which I and many other members of this board have done with no problem.

[jeffrey43]

I appriciate everyones input on this. I think its high head pressure possibly the charge is off and the filter has not been changed.

[hvacvegas]

I appriciate everyones input on this. I think its high head pressure possibly the charge is off and the filter has not been changed.

I'm going to take a stab in the dark, and say that you weighed this goodman in on startup.
Which would mean it's overcharged. Goodman is STILL overcharging their condensers from the factory. Unless I'm getting older stock. Who knows.
If you pull all your refrigerant out (or do a dry system), you can be on the money by weight. If you rely on the factory's 15' rule, your screwed.
Check your normal stuff. 2 month run time could be a filter.

I'm with beenthere on the gauges thing. Only time I've heard of that, is with microchannel package units. I think it was york that realeased that bulletin about their scrolls "losening up" after a few months of run time or something along those lines. If I'm confused, please enlighten me.

Still the idea 410a lying to you is confounded.

[philjafo]

I've never had a problem topping off a system like you say beenthere, even on evaporator coil replacements, only on New system installs, it was explained to me that 410a is a mixture of two refrigerants and something happens to it after the first few hours of runtime. I can't explain it any better but with new installs if they are set to sh sc we always end up going back, weighed in it works so I will continue to set them up the way that avoids callbacks. I would really appreciate it if someone could explain it but I'm not too worried about it

[beenthere]

I've never had a problem topping off a system like you say beenthere, even on evaporator coil replacements, only on New system installs, it was explained to me that 410a is a mixture of two refrigerants and something happens to it after the first few hours of runtime. I can't explain it any better but with new installs if they are set to sh sc we always end up going back, weighed in it works so I will continue to set them up the way that avoids callbacks. I would really appreciate it if someone could explain it but I'm not too worried about it

You were LIED to.

If it was true, then it would also happen on TXV systems.

What brand unit are you installing.