17 votes
Accepted

What causes burn marks on the air handler in the attic?

The burn marks on the air conditioner air handler are from the torch the installer used to solder the copper pipes to the unit. The pipes then go the compressor located outside the unit. Most ...
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  • 53.1k
16 votes

Convert GE Load Center to main breaker

Holy smoke, this is a "Rule of Six" panel! A Rule of Six panel has a "Main Breaker" area with up to six main breakers. All must be shut off to shut off the power. All six have their buses ...
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10 votes
Accepted

Should I install an air conditioner pad on existing unit?

Most units require a pad when installed . at the age of the unit I would probably not try to put a pad underneath as this may create a leak. In 99 the common refrigerant was R22 and the cost of a ...
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  • 95.4k
9 votes
Accepted

Can I just cut power to a central air and heating system, or should I follow a shutdown procedure?

Very few HVAC systems aren't able to handle abrupt power loss. I've flipped the switches on dozens of systems hundreds of times to change filters and perform other service. The gas valve will close ...
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  • 104k
8 votes

Central air conditioner grounding wire size difference

Using a larger ground conductor is fine. Using a smaller gauge wire for grounding was common in the past, but not correct anymore. The grounding conductor should be at least as large as the other ...
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  • 18.7k
8 votes
Accepted

How should I evaluate my central A/C to see if it's working properly?

When the person you spoke to said to measure the "temperature difference between the return and supply sides". What they were talking about, is what's known as Delta T (of the evaporator). ...
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  • 128k
6 votes

Breaker lets more Amps then its max

If a breaker is tripping regularly, that's a serious problem you should look at. That is not normal or acceptable. It means something is wrong with your overcurrent protection, or a defective ...
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6 votes
Accepted

Do you remove an AC Capacitor from the circuit before or after you short it out for safety?

Always short the capacitor as early into the disassembly process as you can. You may accidentally discharge it when handling it or removing it from the unit, and these components have enough energy ...
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6 votes

Do you remove an AC Capacitor from the circuit before or after you short it out for safety?

I wouldn't short the cap to discharge it. When you do that, a huge current flows for a very short time. This current is almost certainly far beyond the rated current capabilities of the cap. You may ...
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  • 415
6 votes

Can I just cut power to a central air and heating system, or should I follow a shutdown procedure?

I would start by turning the thermostat off, including the fan setting to "off" and not "auto". The HVAC breaker should be a 240v double pole breaker. Most homes have four of those. One for the water ...
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6 votes

Time to Replace Central AC?

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 ...
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  • 95.4k
5 votes

Why are almost all of my house's HVAC floor registers placed near exterior windows?

This DOE reference indicates, with better double glazed windows and better insulation, that ducts should not be run in outside walls anymore. HVAC Ducts Shall Not Be Run within Exterior Walls ...
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5 votes
Accepted

How do I interpret a central air conditioner label?

The text Volts 208/230 Phase 1 means the device will run on either 208 volts or 230 volts (which is nominally 240 volts). In the amps section, the separated numbers (which are the same) are the ...
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  • 12.1k
5 votes

Convert GE Load Center to main breaker

Hard to say based only on what you show and describe here. We can't really know exactly what you have without seeing what's inside. The 2 pole 50A breaker what has the word "Main" written next to it ...
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  • 14.4k
5 votes
Accepted

What is a "solar-ready" air conditioner?

You paid a higher cost to have an AC with the built-in breaker circuit to handle the output from a small solar system. The built-in breaker limits the size of the solar system that you can install ...
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  • 2,683
4 votes
Accepted

Can I install A/C in a home built in 1924 which has round heat ducts in the ceiling?

Sure -- or at least, there's nothing about having round ducts in the attic that would make A/C installation more difficult. In fact, because cold air is more dense than warm air, ceiling vents are ...
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  • 8,017
4 votes

Must my new air conditioning unit be 3 feet from the wall (or positioned backward)?

According to Trane installation instructions, the technician is correct. They do require 3' of clear space in front of the control box. As for why the technician chose this orientation, I can ...
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  • 128k
4 votes
Accepted

HVAC supply and return preferred locations

Home heating and a/c duct systems have changed over the years. The best systems and the most versatile were installed with both high and low returns and supplies. For heating the low registers were ...
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  • 12.1k
4 votes

Convert GE Load Center to main breaker

If you were a customer of mine and wouldn't let me rip out that equipment, I would walk away. There isn't a chance in the world I would add additional load to the existing over current protection. ...
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4 votes

Why is the paint around my ceiling air vent discolored?

To me that looks like a water leak that is being pushed by the air flow. I would be checking for a leak above that location.
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  • 95.4k
4 votes
Accepted

How to stop Central Air unit from freezing over inside and outside

There are a few causes for this, and the most common are in two categories - bad air flow and low refrigerant. Bad airflow can be caused by a dirty filter, clogged ducts, or a poorly performing fan. ...
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  • 26.6k
4 votes

Flex-duct as a Trunk?

There may be some opinion on top of what I believe to be true. There are some large flex duct sizes but the ribs are horribly inefficient. Metal trunk is also better suited when going vertical it is ...
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  • 95.4k
4 votes

My HVAC A/C is freezing after sundown every day

A low charge can cause evaporator freezing. If your cap was bad that usually indicates an older system. Micro leaks have caught up, probably R22 and it is getting expensive. A 5 ton system will take 4-...
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  • 95.4k
3 votes

How should I evaluate my central A/C to see if it's working properly?

Delta T after the unit has reached setpoint temperature (if it will) I have always used 20 °F. Latent heat must be gone and now we are reading sensible heat temperatures. If anyone is going to ...
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3 votes

Why are almost all of my house's HVAC floor registers placed near exterior windows?

Originally, homes throughout northeast, north and mid west that were new enough to have central heat, used gravity furnaces located in the basement. With no blower to move the air, the common ...
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3 votes

What causes a HVAC control transformer to overheat?

Underpowered transformer Sounds like you may not have gotten an equivalent replacement. When looking for a replacement transformer, you should be concerned with Input, or primary voltage Output, or ...
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  • 128k
3 votes
Accepted

What to do about different rooms in the house being a completely different temperature?

It's a balancing problem, fairly typical for a one-zone heating system spanning an entire house. Mind you, I'm a bit concerned with a setup that kicks on the A/C in heating season - being from a ...
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  • 132k
3 votes

How do I eliminate the cold drafts coming from my air conditioning vents during winter?

I had the same problem with cold drafts coming thru the ac vents that are not used for heating in the winter (I too have baseboard hot water heating and only use the ac and ducting in the summer). I ...
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  • 31
3 votes

Should I insulate air conditioner coolant pipes?

Suction Line Insulation Insulating the suction line (larger pipe) is done for two reasons. First, it prevents condensation forming on the pipe. Condensation could drip from the pipe and cause damage ...
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  • 128k
3 votes

How much cooling can I expect from a central air conditioner?

We had the same problem in our house, and we've simply lived with it - having had HVAC companies come out and inspect or evaluate it. They all said the system was in good working order, and was ...
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  • 3,223

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