high head low back pressure

[toocoolforschool]

Filter drier clogged....

[SBKold]

Is the tech reading total condenser pressure or liquid pressure?

[KB Cool]

Maybe the cardboard fan shroud is stuck in the blade!!!!!hahahaha

[flange]

I am guessing system is empty. I am also guessing this isa small recip compressor, and guy last used his gages on an r22 rooftop, fogot to purge, and tied high side into king valve, but forgot to open the valve to the access port. he is reading head pressure off the last rooftop unit he saw, and low pressure of the reach in with no charge in it.

[coolerman]

You know Flange, I thought exactly the same thing. I try to get 250# on a identical unit with 134A and the only way I was able to do it was stopping the condenser fan, went up over 350#, but the low side start to climb up as well

[Tommy knocker]

Bad high side gauge, out of calibration perhaps. Doesn't matter really, it's restricted somewhere. Once it pumps down and no more heat can be absorbed head will top out, below the pressure you have indicated if fan is running and coil is reasonably clean. I'd toss out that head pressure data and concentrate on the low suction issue for now. Although if he has one junk gauge why couldn't he have 2? Pull the charge, run a tank of nitrogen through it, vac it down to 300-500 microns, weigh the charge back in. Almost forgot, change the drier. Fire it up with a set of stub gauges, no hoses and see what you have. If it pulls into a vaccume agin replace that brand new TXV and keep the torch off of it. That's the coarse I would take in this situation.

[jpsmith1cm]

Actually, if we're taking this to the level of diagnostics...

Pressures alone aren't enough to make a proper diagnosis.

Have the tech provide Superheat and Subcooling readings for a proper diagnosis.

[coolerman]

I ask him for the subcooling, just to make sure that was a clog and he said I don't need to check for subcooling because he new it was a clog.
I don't get it!!!

[Tommy knocker]

I ask him for the subcooling, just to make sure that was a clog and he said I don't need to check for subcooling because he new it was a clog.
I don't get it!!!

I understand his responce. if the -25 you posted ment 25" vac checking the subcooling is not where I would be headed nor would I be too concerned about SH with the information given. Pressures are at the extreme in both directions. Pretty obvious. That being said I am not saying that checking SH and SC is the wrong thing to do or that its a bad idea. Just saying I myself would go a different direction with the info given.

[coolerman]

That's wy I love this site, everybody as a different opinion but when you mix them all together you come up with a decent diagnostic.
I'm thanking everybody

[frigeguy]

Maybe the cardboard fan shroud is stuck in the blade!!!!!hahahaha

I was going to say ...did you ask if the fan on the condensor was spinning?

[coolerman]

The end result of this "shibang"
Today another tech went there to fix the problem, I call him, he was just finishing the job. I ask him what did he find wrong with the unit, he said, "I put my gauges on, start the unit and the low side went to vacuum and the high side was reading 150# , I found the leak , fix it, vacuum the system, charge it and everything is runing fine".
What the *#*#*? What happened to the 250# on the high side? That's wy wasn't making any sense.
Wy did we lie ? I don't get it!!!

[Tommy knocker]

The end result of this "shibang"
Today another tech went there to fix the problem, I call him, he was just finishing the job. I ask him what did he find wrong with the unit, he said, "I put my gauges on, start the unit and the low side went to vacuum and the high side was reading 150# , I found the leak , fix it, vacuum the system, charge it and everything is runing fine".
What the *#*#*? What happened to the 250# on the high side? That's wy wasn't making any sense.
Wy did we lie ? I don't get it!!!

Bad gauge. I'm curious if the second tech replaced the drier with the leak repair.