ReplyAre you sure the indoor fan is coming on when pressure reagings are low?
Regular Guest
Help!! 2.5 Ton Goodman Heat Pump, when unit first turns on in cool, the suction psi is between 35-45psi, head pressure is between 125-150psi. These pressures hold steady at those psi's for 15-25 mins then both pressures slowly start rising and steady off at 70-75 low and 250-270 high depending on conditions. Problem is if pressures do not start rising fast enough sometimes unit will start freezing at evaporator. Unit does not freeze all the time just sometimes very infrequent. The air filter is clean, evaporator is clean, condensor is clean and evap. fan is running good on high speed. Could I have a restriction at the orifice, but usually the circumstances are the reverse of what i am finding. Any thoughts would be appreciated. The compressor was replaced in April 08 and has been running good up until about a week ago.
Professional Member
Are you sure the indoor fan is coming on when pressure reagings are low?
Professional Member*
Superheat?
Subcooling?
Just because your fan in on high doesn't mean it's right. Have you tested staic pressure to determine CFM?
Sounds like a charge issue to me but without more information, hard to tell.
I need a new signature.....
Regular Guest
Yeah, indoor fan comes on every time.
Regular Guest
How do you test staic pressure?
Professional Member*
Jog.....don't take this the wrong way but if you have to ask, you may need to call a service professional out to evaluate your system. If you are a professional, get your post count up to 15 and apply for professional status on this site. There is a wealth of information on here, including step by step procedures for testing static pressure.
We are not allowed to give out DIY advise on the open forums of this site but once you are professional, we can talk shop all day and night.
I can tell you this....we test static pressure to get the amount of CFM a blower is moving. If you follow the 400 CFM per ton rule then your indoor blower should be moving as close to 1000cfm as you can get. After that is verified, then you can begin adjusting your refrigerant charge using superheat and subcooling measurements.
I need a new signature.....
Regular Guest
O.K. thanks for the heads up. I am not a pro. just a maintenance tech at a n apartment complex, only been in the hvac/maintenace field about a year so this is really the first unit i have had that has given me a problem I couldnt figure out and my superiors think it is a bad compressor but i am not sure and dont want to just changing out parts if you no what i mean!
God Speed, Jim. We'll miss you - 2-26-23
Was it the compressor that was changed out in April, or the condenser.
What are the chances that someone has added gas to get the vapor pressure up.
Professional Member
Still get your post count up and apply for pro status if you get it you will get all kinds of really good info from all of these great techs. Being a rookie does not mean that you are not a pro, it is defined by the way you approach problems and asking questions before making mistakes is the first step in the pro-direction. Good LuckOriginally Posted by Jogalloway
"It's always controls"
Professional Member*
Agreed. If you are working on HVAC equipment as part of your making a living, have a cfc certification to work with refrigerants and are part of the daily HVAC industry, you qualify as a pro.
Because of how long the system operates before the pressures change, there must be a change in the system operation. My guess would be that a refrigeration issue is causing an airflow issue later in the cycle.
Training is important!
Practical Training is a must!
Regular Guest
Thanks guys, compressor was changed in april 08, no problems until last week, lady called office and said she had ice all over filter, another tech checked the first time and said filter was dirty and low charge, he changed filter and charged unit. Lady calls back to the office on thursday of this week and said it was froze again. i checked this time, let unit thaw, turned on cool, hooked gauges up and had 38psi low and 130 psi high, thought to myself we have a leak, walked to shop to get nitrogen etc and other tools, returned to unit about 20 mins later and i had 72 psi low and 250 psi high. Condensor was pulling some major heat out, i cussed to myself a little bit, evap. fan was set to run low speed, I installed black wire from motor to control board to run at high speed you could feel and hear the change in motor when I started back up, cleaned evap. coil and condensor, thought to myself that fan was on low speed was the problem. Turned unit back on, check gauges and it was doing the same thing as before. Been keeping check on unit since friday and it is cooling but just a matter of time before conditions are right to cause it to freeze up again and the lady can yell at me again. Ha Ha
Membership Committee*
Twilli says whats CFC?
No Heat No Cool You need Action Fast
Professional Member
Will need more info. Superheat, subcooling, static pressure, compressor amp draw. Do not get discouraged we all started somewhere too. Keep posting, get that pro status and you will get your answer and a wealth of knowledge at your finger tips. Understand that DIYers can be very dangerous with just a little information and that is the reason that this website screens for its members as well as protecting the industry. A lot of apartment techs (and many other general maintenance techs) just use high and low pressure to verify a charge but that is not the proper way, and do not waste your breath trying to convince them otherwise they are blinded by the ignorance of the reset and run way of fixing things, if you want to be anything other than a rent-a-hack you will learn the proper way to do it. Have patience the pro status has been invaluable to me and several of my co-workers and I am 100% sure that if you are as enthusiastic to do things the right way it will be invaluable to you too, not to mention your value $$$ as an employee.
Membership Chair/ARP Committee / Professional Member*
Right?
PHM
--------
When faced with the choice between changing one's mind, and proving that there is no need to do so, most tend to get busy on the proof.
Regular Guest
Appreciate it skw, will get my post count up and apply for pro cause i have alot of questions ha ha, my supervisor is just a manager so he really only cares about how much it will cost to repair, and the other maint. tech is as green as i am, so i really dont have anybody else to ask questions! The company i work for "supposedly" has a regional guy that i aam to ask any A/c questions but I have called him about 10 times in the last couple of months and he hasnt returned any calls. Thanks again!
Professional Member
ColdFreonCrap, CandyFlavoredCotton, CrapFlavoredCookies, CantFindCrap, CertifiedFunkinClown, CentralFunkinCommitee. I dont know help me.
Regular Guest
You should really consider taking some classes to further yourself in the field. Do you guys use reclaimers and micron gages?
Regular Guest
Ive got a couple of classes coming up this fall, intro to ref. and comfort cooling at local tech school. We have most tools vacuum pump, gauges, micron gauges, recovery machine, recovery cylinders, scales, ox-acytelene torch, a fieldpiece sh/sc meter. Problem is trying to learn on the fly and under pressure without a more expierenced person to ask questions. i have done pretty good by reading as much hvac material as i can find but that cant replace expierence and all the little tips and tricks you cant find in a book.
God Speed, Jim. We'll miss you - 2-26-23
Recover charge. And weigh it back in.
Professional Member
You either have an air flow issue or a leak that needs to be repaired, assuming an R22 system.
Best thing to do is to get a good evaluation from a reputable company and pay them to fix the problem. Easy as pie. Find a company tha guarantees their work the first time and let them figure it out.
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