Time to Replace Central AC?

Question

Have a 2004, Rheem, Model #: RAMC-048JBZ; R-22 refrigerant. We live in Central Texas, very hot 5 months a year, we use the AC probably 7/8 months a year. Have had annual maintenance performed since we bought the place in 2016. Just had it serviced and technician advised us to consider replacing the whole unit because (after cleaning coils, checking refrigerant and capacitor): - Compressor is overtaxed. At 65 deg. inside and 71 deg. outside, compressor is already pulling 12 amps. R.L.A. is 19.2. So this doesn't bode well for our upcoming 100 degree days. -Disconnect fuse and housing mounted on outside was partially melted. This may explain, last year, a blade on the condenser fan partially broke and continued to spin inside the system until I heard it and shut it off. I then installed a new condenser fan last summer. -Coils are clean; refrigerant remained charged over past year; capacitor is, apparently, good.

Is it time to replace this entire 16 year old unit? Or should I try to replace compressor myself? Compressor retails around $1300. Will be getting another opinion/estimate from another company.

Thanks yall.

UPDATED PHOTOS OF DISCONNECT BOX AND FUSE

Answer 1

The disconnect burning up is a sign of loose or corroded terminals which create a high resistance at the connections. As the current drawn stays the same, this generates heat to the point where it overheats the contact and worsens over time.

Part of the tune-up is to check and retighten all electrical connections. Especially the screwed in kind at the junction box and on the compressor contactors. This is more often than not not done.

Another problem that may affect you going forward is the formerly standard practice of checking refrigerant pressures during a check up. Every time gauges are hooked to a system some refrigerant is bled off and eventually needs to be replaced. The latest thinking is that gauges should not be hooked up unless there is a problem that is not corrected by changing air filters and cleaning coils and fan blades.

And check out Bluon, an R-22 replacement Refrigerant that claims to work better than R-22 and at lower pressures. I believe it is R-458A but you should check out the Bluon site.

I think your system is working fine. My York heat pump was 25 years old when I replaced it due to remodeling and reducing. Duct systems are usually not allowing the HVAC system to perform as well as it could. Good luck! A hard start kit adds a capacitor to the start circuit which is removed from the circuit by a potential relay when the motor gets up to about 80% of it's rated speed. See linked article. The checking HVAC systems article is from 2005 and is slowly gaining traction within the industry. It avoids wasting refrigerant and introducing contaminates into the system.

https://www.achrnews.com/articles/94470-checking-the-charge-without-gauges

https://www.achrnews.com/articles/119718-the-case-for-hard-start-kits

https://www.bluonenergy.com/

Answer 2

Is it time based on the power consumption? I will try to be polite but Hell No. when your system is running at full load and hot the power may get close to RLA , RLA is like FLA for motors. If they are drawing less they are not fully loaded. Having a worn out compressor could cause a lower power consumption but then electrical parts would not be overheating. If your system is leak free it sounds like it is keep it clean and you may get another few seasons out of it. R22 is obsolete and cost an arm and a leg at the time your system starts under preforming, then a compressor replacement could be an option but this is NOT a diy job, the Freon would need to be removed in a recovery system the old compressor cut out and replaced with a new filter dryer then recharged with the old r22 , just note if there is a leak it will be cheaper to replace the system as R22 is going 100 per lb and up, but it is still available but expensive. Your system takes 10 lbs and even if you need to change the compressor the Freon is still good. But you may need a few lbs to top the system normally less than 50% for a functioning system in my experience. If you see your power bill jump, compressor starting to run all the time and may not be cooling as well with the same temps as last year this is when the system needs more than a annual check up.

Answer 3

Right off the bat, the one item that really sticks out is the partially melted fuse holder and disconnect box mounted on the wall. That should be fixed before doing anything with the AC unit. There could be bad connections in there that could cause inefficiencies in the AC unit. Replacing the AC compressor would be a mistake in a 16 year old unit. If you're going to correct the problem now for piece of mind, replace it unit and don't forget the air handler. I'd be tempted to wait and see how it preforms before just replacing it.

Answer 4

The disconnect is cheap and easily melts, check for a bad connections, start amps.

I would recommend a 521 start kit and most likely a contactor. I have replaced a contactor and installed a start kit. The start kits are great one unit went from 133 start amps to 7 start amps. I have a video I showed my client, being an electrical engineer he was amazed.

12 amps running is nothing to worry about.

Make sure the indoor and outdoor coils are clean, some Rheem units have a z coil and are a pain to clean. If your coils are dirty the pressures will be off.

I have been an AC tech for 14 years the old rheems are great units.

As for r22 how many pallets do you want I'll be able to get it for a long time. And it is not that expencive.

If you have a small leak charge it and put in a leak sealer from nucalgon.

When I check out a unit I always ask the client to come with me if it is not on the roof, if they have their own ladder they are welcome to come with me.

I could go on and on about "techs" scaring people about the r22 scam.

New units are pushed by techs, as for the new units look up coil leaks, after 2 years alot of the manufacturers has leaks in coils and your labor and refrigerant are not covered.

In my humble opinion get another company to come out.

Every company I worked at would put the repair cost twords a new unit if it failed.

In 14 years of being a HVAC technician, I have 3 people I would trust comming to my house, half my business is referral work. If someone needs a unit I have friends with small companies I refer to clients.

Answer 5

If I recall correctly the only real test to determine potential remaining life of an compressor is a megohmmeter test. Basically a highly advanced resistance test of the compressor's motor windings. Most HVAC techs don't have megohmmeters. Most schools don't train techs how to use 'em. It requires having a baseline.

In short: if the compressor runs my advice is let it run until it dies. Meanwhile start saving for a new system.

Answer 6

First of all, that "tech" doesn't know his @$$ from a hold in the ground. He fed you a bunch of BS to get a sale on a new system. He probably worked for one of those "we do a/c checks for $49!" Companies right? They arent technicians. 75percent of their training is on sales. They come come out, diddle fart around a unit, come in with a bunch of photos (preloaded into their phones) to hustle you into buying a new system. Mainly because no company could afford to do checks at 49 dollars so that tech was probably making 15/hr but makes 5% on a 6-12 thousand dollar sale. So back to the start. You cannot check an a/c unit accurately, when there is no load on the space. How hard do you think it was for the AC to cool 65F air? Especially when it was only 71F outside? Your r22 pressures are going to be much lower than normal because of those 2 factors. As for the disconnect oull, if you didn't see it with your own eyes then I suggest going and looking for yourself. 95% of the time it's a lose connection in the disconnect especially pull types. Heat is created by resistance and the wire and the disconnect should be Amp rated for the unit. The AC would have to be pulling lock rotor amps for abnormally long time to produce that much heat. Let your system go for the summer after having the disconnect replace with a Square D switch type. Then if you feel that it's not keeping up on an 80F day, call another company who has a good reputation. I have 20yrs in the field and have seen so many people be bamboozled by other HVAC companies. That's why the trade has a horrible stigma associated with it.

Answer 7

There is no reason to replace an AC unit that's working and not leaking refrigerant. Newer refrigerants/units are not more efficient in any significant way that will save you money, certainly not more than the cost of replacing a unit earlier than you absolutely have to (note that installing a new unit 3 years sooner means the expected end-of-lifetime for the new unit is also 3 years earlier, so this is absolutely a cost).

The tech's claim that the "compressor is overtaxed" is meaningless mumbo-jumbo. Unless it's running at 100% duty cycle and still not getting your home cool, it's not "overtaxed", and moreover you want it to be running at high duty cycle because that's how you get rid of humidity. AC salesmen will try to sell you oversized units that run at really low duty cycle and will leave you with something like 70-80% humidity at 73°F, requiring you to over-cool to get comfortable.

Answer 8

Probably time to replace. I am in the Houston area and sympathize, but these consumer units are designed for finite life. I basically do all my own work on the house ,Except AC. One problem is that you need a license. I did install my own central unit before the restrictions. Now I have a contractor I trust.In this house the original compressor failed after 10 years. The replacement failed after 15 years and I had whole unit replaced. A footnote, the county sent out an inspector after the new unit was replaced. And ,of course, many capacitors, contactors, etc. were replaced over the years.

Answer 9

I would not change the compressor if it's running it's usually okay I would wait until it gets warm out and see how it runs before I would change it out a new compressor from Rheem would probably only cost $700 not 1300 I would check my insulation in the attic and make sure everything up there is okay cuz that's usually more of a problem in an older house

Answer 10

Compressor won't come on if it's low on refrigerant due to a low pressure switch to keep compressor from burning up. Most of the time the unit is just a little low on refrigerant. This can be due to guages being put on and off over time for service checks. Also the coils on outside of unit when mowing a rock hits it or some object and puts just a small enough hole in line to release refrigerant or a shredder valve where you hook up guages could be bad. You would know if it's leaking out of shredder valve after taking caps off because their would be signs of the poe oil in cap and around valve. Most time system is old and just needs a little bit of refrigerant added due to prior check ups. If you turn your system on and don't hear compressor running hook up your guages and look if you are low. If low just a little add some refrigerant and listen for compressor to turn on due to it's low pressure switch to keep it from running when it's low so it doesn't burn up. Change your dude if it's melted. Check the start run capacitor. If it's swollen you know it has to be replaced. Check the relays make sure they are turning on and function correctly by using a jumper wire. You will hear the click. Clean your inside and outside coil with soapy water and coil cleaner and wash them off. Had a company charge me 120.00 and only used water hose to clean outside coil and didn't even brush the coils to straighten them out. And walked off when I called him out on his work and was watching him the whole time. If you line freezes you are low on refrigerant and need to listen to compressor. If it ain't running it's obvious system is low. Companies want to bend people over because they know they need HVAC to keep them comfortable. I am a disabled vet and thank God I remember a little from school and fix my sister's, my mother's and mine. R22 for 10 lbs I paid 250.00 for not to long ago .