My 1986 Lennox AC compressor unit just stopped running, the fan isnt running and no noise comes from the unit, I reset the breakers and the thermostat is the old round analog Honywell, its calling for cooling. Ive never worked on this but is there anything I can test with a V meter before I call a pro. 3 weeks ago I lost all freon from a big leak and had it fixed, all has been fine until today. I would think at least the fan would run.
When this happened to my 1991 Lennox, it was the timing board. That particular board delayed turning the thing on for 5 minutes once it was told to by the thermostat. This was to make sure the old mercury therms had time to settle and prevented on-off-on-off. The tech said it was pretty obvious that the board burned out. One possibility?
If there was a thunderstorm, a voltage spike could have blown the run capacitor. If your air handler fan doesn't run, it's a power problem there because the 24 volt control voltage comes from the furnace/air handler. Without the 24 volts AC, the condensing unit where the compressor is will not come on. If you can push in the insulated contact carrier on the condenser contactor and the fan and compressor run, you'll know it's not getting control voltage from the furnace/air handler.
TDD
Is there some specific reason you want to keep fiddling with a unit that is 24 years old and now using a substitute refrigerant for what it was originally charged with ?
After fixing a leak the unit stops working completely ?
I would say you got your 24 years out of the unit and its time to update your installation... Not only will a newer unit of the same size use less energy, they also have better control systems for them now...
~~ Evan
My mistake its a 96, only the second time it broke, its 13 seer and I could not get a new one this year, so its fix it or get a window unit for the room I sleep in.
What does the condensor contactor look like where do I find it, I wonder if the tech left a wire loose since it seems like it just has no power. I do know I dont think it was installed with proper gauge wiring , Its about a 60 ft run of 2 pieces of 10 ga and it rattles in the pipe and at the breaker on turn on. All these years of rattling could have loosened something.
Wouldnt the fan run even with a bad capacitor
That sounds logical
I'd start by seeing if you have 240v coming into the outside condenser unit. It comes into a relay that gets closed to turn on the compressor. If so, then see if the relay closes and you get 240v on the other side going to the compressor when the system is turned on
It's the only (usually) relay-looking-gizmo in the outside unit. It supplies power to both the fan (120) and the compressor (240). If both are not working, the obvious culprit is the only thing they have in common - the relay.
That said, it could be the relay itself is broken (fried, etc.) or the voltage that activates the relay (24V) is missing.
If the relay, they're not TOO expensive and, if your hand fits a screwdriver, you should be able to replace it. Label the wires - taking several pictures is better - and take the old one to Graingers. Say "gimme one like this".
Remember to wear eye and ear protection when working around electricity and, um, er... one other saftey precaution, but I forget...
I've never heard of a wire or a breaker "rattling". The freon lines on some units can be noisy and that might be what you hear.
You can check for 240vac at the unit. It should be easy to trace to the contactor (a big relay). The contactor is a 24vac activated relay that supplies 240vac to the entire unit. The inside half sends the
24vac. It is possible to manually activate a contactor by pushing it down carefully with something. The compressor and it's fan are both activated by the contactor. If there are any additional controls such as the startup delay board they will most likely be on the 24vac side. Both the compressor and the fan will use run capacitors but they may be combined in a single can. Ther may also be a start capacitor on the compressor. Since nothing is running I doubt it's a capacitor.Yeah, we can't tell him the other safety precaution. It's too complicated.
I think he will find that the condensor fan is also 220 VAC. And has a run cap.
As others have suggested. You can check to see if the outdoor unit has
220 VAC. You can also check to see if the contactor is getting the 24 VAC signal, and if the contactor is making connection.The fan and compressor have different capacitors. Possible but not likely that they are both bad at the same time.
I can hear the wires "Rattle" inside the conduit and the breaker on the main panel makes a zip noise when it powers on, I bet it should have been a larger gauge but they had no more room in the conduit. I mentioned it to them on install and they said 'its ok", but I know it would have been rejected by an inspector. I didnt get a permit or an inspection for the install, In 96 I didnt think permits-inspectors were a help. Thats why I wonder is I have any power since nothing works, but im no electrician.
quoted text -
Yes AC power is where I will start at, I cant even find my meter today, but its only 72 out.
It sounds like you're not very experienced with electricity. Do you have a friend, or relative you can call, who has some electrical experience? Some things are best learned from an experienced teacher, rather than on the internet. This is one such.
My HVAC took a time-out a few weeks back. Nothing would work at all. The fan would not even run, like yours.
I presume the fan blower gets its 110V power from a light switch box in the attic. The switch had failed and no power was getting to the blower fan.
YMMV
If the inside unit is not working then it's likely that the 24 vac transformer is not getting power and that will explain why the outside unit doesn;t work. The op was not very clear about the inside half but I got the impression it was ok. I could easily be mistaken.
Wires will never move due to being energized in this application. They will get hot if they are too small but they won't "rattle". You are hearing something else.
When I push in the relay it runs, so now I will go back out and see if its getting 24v.
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