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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.

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UPDATED PHOTOS OF DISCONNECT BOX AND FUSE

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    Smells fishy - on the other hand, getting out of expensive R-22 and on to a modern refrigerant in a more efficient unit... but smells fishy. One of the folks that does more AC stuff should be along shortly. – Ecnerwal Apr 27 at 16:48
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    Keep in mind that while I am sure there are differences in how a compressor runs depending on ambient temperature, in the end it is either "on" or "off". It is more "on" than "off" when it gets really hot outside, but it is essentially a binary system - full power or no power. – manassehkatz-Moving 2 Codidact Apr 27 at 17:36
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    There are some exceptions - e.g., often an air-handler will have a low speed and a high speed - and depending on issues of humidity or other factors, low speed might be better than high speed even though it wouldn't cool the house quite as fast. But by and large, residential HVAC is all-on or all-off. Much like (as I have had discussions with people who don't "get it"), a typical tank water heater is either on or off - setting it to a higher temperature makes it run longer to get from cold to very-hot (instead of cold to hot) but doesn't actually increase the rate of heating. – manassehkatz-Moving 2 Codidact Apr 27 at 17:49
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    The system is almost binary and depending on type of control throttle valve vs orifice the load varies ( with a throttle valve) Rheem being a higher end unit usual do have throttle valves normally referred to as TXV’s . Those inexpensive disconnects do fail over the years many times when a cap starts going bad the start up current increases heating poor connections , I did not see the photo of the disconnect when I answered but it needs to be replaced. As for the compressor that is not a diy job first legally. 2nd a recovery machine and holding tank cost~1500.00 + gauges and line set etc. – Ed Beal Apr 27 at 19:27
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    "Compressor is overtaxed" is a bs non-problem to sell new AC units. – R.. GitHub STOP HELPING ICE Apr 28 at 3:57

10 Answers 10

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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/

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  • I do agree that if a standard gauge & line set is used a lot of Freon is lost. I have a set of gauges that directly connect to the ports , no lines, yes some is lost but this is the only way to verify the system is ready for the season, not checking could allow a system to run undercharged causing some damage or excessive wear and higher utility bills, I do know some techs that don’t care and still connect there full manifold for a pressure check. – Ed Beal Apr 28 at 13:36
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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.

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  • Thanks Ed. The rationale is that the compressor drawing 12 amps right now when it's 71 outside is a bad sign for when we hit 100+ degrees. But I get your point that 12 amps is still only ~63% of capacity. Appreciate it! – David H. Apr 27 at 17:27
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    Fire up any electric motor guess what they draw close to 50% of fla with no load in most cases , when the system is not having to work hard (it’s cool) reduces the amount of work being done. You are being suckered believe me I am a licensed electrician and have a universal HVAC license epa 608 and 609. I don’t do hvac full time but that’s exactly what I was doing all last week on several systems. – Ed Beal Apr 27 at 19:12
  • Definitely agree with your motor assessment... + – JACK Apr 27 at 19:16
  • Good answer and much more concise than I would have been. R22 is almost $125 through most places near me. If you get to 5 lb then the math starts taking over and might as well replace. – DMoore Apr 28 at 5:10
  • Technically, w/o a license, diy is the only legal thing you can do: do-it-yourself to your own equipment. You need a license to buy refrigerant, and to work on equipment that you don't own. – Mazura Apr 29 at 0:23
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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.

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  • Hey Jack! Thanks for your thoughts. I hadn't considered that the fuse may be the source of the problem. I just included a few pics of the disconnect box and fuse. I'm having a different tech out on Thursday and will ask about replacing the box instead of the whole darn thing or the compressor. – David H. Apr 27 at 17:28
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    I thought that was fixed I agree it needs to be fixed more likely a cap going south causing that overheat. – Ed Beal Apr 27 at 19:05
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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.

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  • Hey Brian! Thanks so much! Will look into the start kit. I'm not familiar with it, does it replace the capacitor or is it in addition to it? – David H. Apr 28 at 15:16
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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.

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  • This is wrong a megger only tells you if the motor insulation is good at that point in time, I have seen a system go acidic when a new filter dryer was not installed and wipe out a brand new compressor in less than a week. The seals and valves are the wear points just like a car engine when excessive wear the motor lacks power. When a ac compressor has a stuck discharge valve or the compressor is worn on a hot day the sub cooling and super heat will be below specs with no way to get there. This is why gauges are needed. – Ed Beal Apr 29 at 2:51
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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.

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    I give an up vote for everything but the disconnect. A loose connection can do much worse than that including burning 500mcm wires off at the lugs, most of the time I find overheating it is a bad cap causing a hard start. But other than that I agree. – Ed Beal Apr 29 at 2:40
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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.

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    what's wrong with helping ICE? Really we are naming ourselves to stop helping protection agencies? – DMoore Apr 28 at 5:11
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    @DMoore, maybe he's a Tesla shill and really wants the Internal Combustion Engine to die? – JPhi1618 Apr 28 at 5:24
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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.

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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

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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 .

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