High efficiency furnaces just as with any other mechanical devices can have problems. Recognizing what the problem is, what is causing it, and how to fix it can be difficult for anyone who is not well versed in how a high efficiency furnace works. Here is an article published in The Bradenton Herald and written by Angie Hicks about a leaky high efficiency furnace:
Ask Angie: Furnace Leaking Water
By Angie Hicks-http://www.angieslist.com/
Why would a furnace leak water at the base? The filter is wet also.
Brent T., Indianapolis
Dear Brent: There could be a few reasons why your furnace is leaking water, but let's start with the most likely one: a condensation leak. High-efficiency furnaces those with an Annual Fuel Utilization Efficiency (AFUE) rating of 90 percent or higher have cool exhaust, and as a result, they produce condensation. An easy way to tell if you have a high-efficiency furnace is to look at its vent pipe. If the pipe is white plastic (PVC), you have a high-efficiency furnace.
Typically, the condensation from a high efficiency gas furnace is channeled to a floor drain. Your leak could be a result of the condensation tubing becoming clogged or from breaks in the line. It could also be a result of the drain becoming clogged. A standard-efficiency furnace which has a metal exhaust pipe should not have condensation. If it does, it could mean that the flue pipe was incorrectly sized. That could allow the hot exhaust to cool down and condense in the pipe, then drain back to the furnace and leak out. If you don't have a condensation issue, it's possible that the secondary heat exchanger in your furnace is the source of your leak. Let's hope not, though. That could be an expensive fix and might even require a complete replacement of your furnace.
You could also have an issue with your humidifier, which could be leaking inside your furnace. If you've had an annual service check, as you should, this is an unlikely scenario because your service technician would have alerted you to the issue early. If you have neglected that service, you should call for it now because if this is your problem, the leak could do a lot of internal damage to your furnace. There is another possibility. If your air conditioning unit is still operating and it shares an internal drain with your furnace, you could have an internal drain system plug, which is sending water to the furnace.
While we can't diagnose your issue precisely, don't let this go too much longer. Leaks can cause huge issues including damaging parts, flooring and walls and lead to mold growth. It's a clear sign that you need to call in professional help. A reputable heating and cooling specialist should be able to quickly diagnose the leak and offer solutions to your problem. Do your homework and get more than one estimate before you act, but get started now. Angie's List collects about 40,000 consumer reports each month covering more than 350 categories of home-related services. Angie Hicks compiles the best advice from the most highly rated service pros on Angie's List to answer your questions. Ask Angie your question at email@example.com 2011,
The above material is quoted from the Bradenton Herald.
As with most modern devices the technology advances in furnaces have made them ever more complex in construction and gas furnace prices are higher than ever before. This means that what might have been a do it yourself job on an older furnace is now beyond the capability of the average home owner. Calling a qualified service representative is really the only way to go when it comes to having work done on your high efficiency furnace.
For more information check out gas furnace prices and high efficiency furnaces