I had a new heater installed this winter. There were two installers: one guy who did almost all of the work and another guy who spent most of the day outside talking on his cell phone. The cell phone dude was the working on the outside unit.

We tried to test out our a/c today, and guess what? It's not working. I went outside to investigate and found the cap for the freon nozzle laying on the ground next to the unit. Yes, it's been off for several months.

Did I mention that the a/c is only three years old?

Okay, so my question is this: Would the freon cap have anything to do with why my a/c isn't working now? Seems like it would to me, but I'm totally ignorant on the subject. I look to you experts for the real answer.

Thanks in advance

I think the cap is just to protect the valve, and being off will only cause problems when somebody tries to service it.

For help getting A/C going, we will need to know a little more. Is it a heat pump? If you aren't sure, check the sticky at the top of the forum.

Wilsoch, it sounds like the cap you are talking about covers the Schroeder valve (like those used in the valve stems of your car's tires) that are used to test pressure and add or remove the freon.

I have found more than a few of these valves left uncapped and they were the source of long term slow leaks.

So it has been off for a few months? There is a chance that the system has lost some of its freon charge. Get someone to check the freon charge. It if is low enough, in some systems only by a few ounces, you will not get any cooling.

Wilsoch, it sounds like the cap you are talking about covers the Schroeder valve (like those used in the valve stems of your car's tires) that are used to test pressure and add or remove the freon.

I have found more than a few of these valves left uncapped and they were the source of long term slow leaks.

So it has been off for a few months? There is a chance that the system has lost some of its freon charge. Get someone to check the freon charge. It if is low enough, in some systems only by a few ounces, you will not get any cooling.

Yes, that's exactly it. It's been left off for about four to five months.

Thanks for the answer.

Wilsoch, so the unit was low on freon, right?

Wilsoch, so the unit was low on freon, right?

Not sure yet. I'll probably have the guys who installed the heater come check it out next week. I'll let you know.

I just can't imagine what else would be going on with this three-year-old air conditioner that worked fine before they put in the new heater!

So what kind of a heater did you have installed, and what is the problem? If the outside unit isn't running at all, it could a loose wire or a bad relay. If your heater is a heat pump, it could be the reversing valves. Not sure if it is, see the sticky at the top of the forum.

If you are low in Freon, a heat pump wouldn't have heated in the winter. If it is an A/C, the inside coil would frost up. Check it after the unit has run for a while. The coil is in the last section before the ducts going to the house. You may have to remove a plate to see inside. I still don't think that cap would have made much difference if you are low in Freon.

Labman is correct, we don't have enough info. Leaving a cap off a Schroeder valve doesn't cause the freon loose unless the valve failed to start with. The cap gives only slightly more protection than a dust cover. Biggest strting question now is does your compressor make any sound? As Labman states, you may have a power problem. If you invite the installer back tell the service desk that you want their tech supervisor, not the cell phone guy with the short memory.

Wilsoch, you say they installed a heater. I guessing it was NOT a heat pump but some type of fossil fuel furnace, right? And I'm guessing that this is the first time you have tried the A/C since the heater was installed, right?

A quick check you can do yourself, would be to make sure all the breakers and disconnect switches are in fact turned on. Most repairmen will turn off the outside unit at the disconnect switch. It is located outside the house, near the outside unit. (If it was installed according to code, it MUST have a disconnect within easy reach of the outside unit.)

The cell phone guy may have pulled the disconnect handle and simply forgot to turn it back on. There are two types of disconnect switches in common use today. The better ones have a handle on the right-hand side of the switch box that must be in the "up" position to send power to the outside unit. On some others you have to lift the cover/door and pull out the jumper plug to turn the switch off or on. (Be on notice, the plug can turned upside down and replugged into the box and it will be in the "off" until it is removed, turned over and plugged back in.) Some of the disconnects may contain fuses and they may have blown. If you find the disconnect switch or plug has fuses, stop by the electrical department of your local Home Depot and have someone test the fuses. Also, ask to see the different types of disconnects... and ask how they work. The few minutes this takes, will make the lesson learned worth it.

If all the breakers are on and the disconnect switch is on and the fuses (if any) are OK, have someone operate the thermostat, moving it from the heating mode to the cooling mode while you stand near the outside unit. If you hear the compressor start or can hear some of the relays click on and off that will give us some additional clues to work with.

Or maybe during the heater installation, they disconnected or broke some of the thermostat wires that control the outside A/C unit. The most likely scenario is they screwed up the low-voltage wiring, an easy mistake to make when trying to connect different brands of HVAC units to the old or replacement thermostat. All manufactures DO NOT use the same color codes for their thermostats and controls at the indoor and outdoor units.

Like ballengerb1 said above, you need to tell us more about this problem before anyone will be able to provide you with a reasonable solution. If you are not able to answer our questions... your only solution is to get the answers from someone who is able to look at your total system.

I hope this was of some help, bvalva

If you have any thought at all that the problem is being real low on freon then do not attempt to run your AC. It could damage you compressor if it is still in working order.

The heater is a Bryant Plus 90 High Efficiency condensing gas furnace.

The outside A/C unit does come on. It seems to have power. It does not, however, blow cold air. It blows air, it's just not cold.

Shut down the ac compressor and have the freon pressure cehcked. Do not run it any further until the pressures are corrected