Air Conditioner...

Got up Saturday morning, Mom informed me the AC stayed on all night, never cycled off. This is a 3 ton central unit, 15+ year old Carrier, so it's on borrowed time.

I open it up, exactly one half of the evaporator was iced up, the other half was sweaty cold, but not iced. It has iced up before when it was low on refrigerant, but never only half! Never seen that before!

So, I turned the compressor off, left the fan on to thaw it, changed the filter. It was somewhat clogged, but not too bad. Waited about 3 hours, turned the compressor on. But it didn't come on!

Checked it out, power to the compressor, but not running, open leads. Had to take the fan off the top of the unit to get to the compressor, it's been off about 4 hours now, and it was still so hot you couldn't touch it!!!

Waited about 3 more hours, got my amp meter ready, tried it again, it started! To me, it sounded a little different, but may be my imagination.

Still wondering why it got so hot... Thought maybe the hard start had stuck in circuit, had the amp meter on the start cap when it started, but it started and dropped right out.

Checked the amp draw on the motor, it was high. Rated at 17.4 amps, it was drawing 21! Checked the run cap, nothing... The run cap is open. Don't have a new one, nothing open to go buy one. But it's running, not turning it off!

And so far, it has run. Cooling as it should, cycling, not icing, but it is running over amp. In fact, I noticed my electric use for the last week has been higher than the previous weeks when the temp was higher. So Monday I will replace the run cap, see if the amps come down.

And... Price a new heat pump system while I'm there! I think it's giving me fair warning, it's about time!

Might want to check your charge. Could be a lil low. As for a replacement try your local supplier warehouse. Commercial company's almost double the price when they put it in. Bought a 3 tone condenser unit for $900 this spring. Just a/c no heat pump.

I agree with you on the charge. Down at work they have that happen on the ice machines. If you don't get this fixed like RIGHT now you will blow the compressor. Most likely you have a leak in your outdoor condenser. Animals like mice dogs etc. take a piddle on it and it rots. My neighbor does HVAC and replaces them all of the time. Mice are the worst in this area with nests inside of the units.

My last AC lasted 30 years before compressor died. My current Rudd central is 15. I don't consider it to be on borrow time because where I live my AC only is used about 90 days a year. On the other hand 15 years on a heat pump is borrow time because the hp is used more days a year. Half iced up, low on Freon. What is your suction pressure? What Freon? No compressor will start without run capacitor. Remove all 3 wires on compressor. There will be an electrical path between an two wires, usually all ohms are close together, very small. Try another cap. A three ton will be about 35 mud.

If you have a question,post it so we can chew on it. I have one,are you reading 21 amps off a compressor lead or between disconect and contactor?

Follow up...

I put the new run cap on this evening. Brought the compressor amps down to 16.4! Sounds better too, had a slight rattle to it, but now it sounds like it used to. Seems to be cycling sooner too, wondering if the compressor speed was down due to the cap being bad?

I still want to replace this system before winter. This is not a heat pump, just cooling with resistance heat. I wanted to get some prices on a heat pump today, but the counter man that will work with me wasn't there. I'll try again later.

Thanks!

Steve, If it was my money, I would use AC until it dies. Heat pumps are over rated. When you need them the most, they don't work. They switch over to resistance heat, so why not just use the resistance heat you have? Ask the sales man who is selling you a heat pump if during defrost are you in the air conditioning mode? Yes you are removing heat from your house to defrost. That means heat pump is sucking heat out of your house and you are on resistance heat during defrost. So is defrost cycle lasts 5 minutes, it will take another 5 minutes to recover the heat you lost while air conditioning.

Google life expendency of HP. Good chance a heat pump won't last past 15 years, my boy's didn't.

Geo, I've been weighing that decision for a few years now, still not 100% sure on the heat pump... They do seem to work well here in Texas. It gets cold here (to me anyway LOL), maybe upper teens, but doesn't last too long. My heat bill is always higher than my cooling , thinking it's easier to move heat than to make it!

I don't think the new heat pumps go into defrost, just switch over to resistance heat and turn off the compressor when it can't keep up. I replaced a 20 year old Coleman heat pump system for a friend a couple years ago. That thing was enormously complicated, freeze stats, ambient air sensors, circuit boards, relays... Too much to go wrong, and it often did! The new Goodman was very simple, (granted, it's cheap too, probably won't last 20 years), but I didn't see any means for it to go into defrost, or to know when it needed to go into defrost... But he hasn't complained, so I assume it's working like it should.

I'm thinking about replacing it before it dies so I can plan to do this during the fall when I can be without heat or air for a few days. Don't want to have to put Mom and the family in a hotel while I replace the AC when it's 100*!