Tag Archives: AC repairs

Do You Have A Leaking AC Evaporator (Indoor) Coil?

In many of my blog posts, I go into lots of detail.  For this post, however, I’m trying a shorter format for two reasons: a – our readers are busy, and want useful information in bite-sized pieces; and 2- the causes of leaks in AC evaporator coils seems more varied than the solution.

Symptoms of leak in indoor coils

  • Periodically being told that refrigerant needs to be added
  • AC system and fan runs, but warm air comes from vents

Causes of leaks in evaporator coils

In the HVAC forums I monitor, the posts on leaky indoor coils tend to come in waves, sometime focused in certain geographical areas.  Humid climates tend to increase some of the issues.  Lately the number of posts has been high.  Leaky coil issues are fairly widespread, and are not limited to any particular brand. Listed below are some of the possible causes of leaks:

  • Corrosion of tubes (“formicary corrosion”) increasing due to “tighter” house construction. Corrosion causes pinholes in the copper tubes
  • Corrosive gasses or fumes from defective drywall or other building materials, contents, or household chemicals.
  • AC coils being made of thinner-walled, lighter gauge copper
  • Higher operating pressures in newer equipment
  • Manufacturing defects in tubing

Possible solutions and questions to ask your contractor

  • If your AC and heating system is older (10 years is a benchmark used by some of the municipal rebate programs) or not very efficient, before doing a major repair, such as replacing a compressor, coil, or heat exchanger, you should also compare the cost of replacement.  Most rebates and tax credits require the installation of a new system to qualify.  Plus you’ll lower your monthly utility bills and future repair bills.  If you are in a position to possibly replace your system, you can use our free grid to compare bids.
  • If your AC and heating system is otherwise OK, ask your HVAC contractor if either a plated (tin) or aluminum corrosion-resistant replacement coil will work in your equipment and situation. If you don’t have a reliable service company, you can visit this page to learn how.

If you have experience with a leaky AC coils, either as an owner or technician, please enter your comments so others can learn.



Maintenance or repair of your AC and heating system: pay a little now or pay a lot more later

Would any reasonable person wait until the engine of their car seizes up to think about checking or changing the oil? Of course not. In addition to the inconvenience, repairing or replacing a car engine costs a lot more than an oil change. Therefore, most people have their car serviced two or more times each year or at certain mileage intervals.

Why then, do so many people wait until their home or building air conditioner won’t cool or their furnace won’t ignite to call their HVAC service company? Not only do they have to pay more for repair or replacement than they would have for air conditioning or heating system maintenance. On the first really hot or cold day in their area, people who skimp on having their A/C and heating system maintained usually line up behind their neighbors who did the same. They might even have to stay home from work to meet the service company when repair calls get backed up.

Having your HVAC system put on a yearly schedule of having the A/C serviced in the spring and the heater tested in the fall saves money and time. The monetary savings aren’t limited to repairs either. A good example is found in the way air conditioners run. A home A/C system will run and produce cool air, even if the refrigerant (often known as Freon) is somewhat lower than optimum. However, it won’t run or cool nearly as efficiently as it would at optimum levels. The result: you can save on utility bills every month, plus have fewer or lower cost repairs and save time with a well-tuned system.

With the direct cost of oil bumping $110 per barrel (not to mention the indirect costs and concerns) we should save on fossil fuels and electricity every place we can. Since nearly everyone uses heating and cooling daily, scheduled HVAC maintenance is an ideal place to start. Do it now and you will avoid the summer rush.