It was a Saturday afternoon a few years ago, and my wife went into our guest bedroom to take a nap. Whatever sports event I was watching on TV was suddenly interrupted with “Honey!!” I jumped up and ran into the bedroom to find the ceiling falling in the middle of the room over the bed and ceiling fan! Going into the attic, I discovered that the overflow pan under the evaporator core of the air conditioning system was partially stopped up and holding water on the back side of the pan, not readily viewable from the front of the unit. It had been going on for so long that a pin hole had rusted in the pan and then water drip drip dripped into the insulation. The insulation became saturated and then the sheetrock became soaked and lost its integrity. The sheetrock began sagging and the seam finally broke from the weight of the wet insulation. I was actually able to stick my arm through the hole created in the broken sheetrock! It created a huge mess that was quite costly and time-consuming to repair! And it could have all been prevented…
As part of your attic system, there are overflow pans and drains that are very important and must be connected properly, clean, and in good condition in order to function properly and prevent major damage and costly repairs. Checking these is part of a regular home inspection. Let’s talk about the two most common items in the attic that need to be connected to pans and drains that will work properly when needed – the HVAC system and water heater.
The HVAC System…
The evaporator core of your air conditioning system creates condensation that must drain effectively through the primary drain line. Depending on the age and construction of your home, the primary drain is generally constructed in one of three ways (1) to a sink trap in a bathroom, (2) to a stand pipe in the attic that drains to a sink trap, and/or (3) to the exterior. Whichever drain system is present, it needs to be regularly cleaned. Slime and debris can get in the primary drain line and it must be kept clean to be free-flowing. The associated sink trap must also be kept clean and unclogged so it will drain effectively.
The overflow pan under the evaporator core in the attic is a safeguard system in case the primary drain is clogged up or not working properly. The overflow pan is connected to a drain line to the exterior, generally to a soffit above a window or to an exterior wall. If water is ever dripping out of the secondary drain pipe, it is an indication there is a problem with the primary drain. The overflow pan must be kept free of insulation and any other debris that can clog up the drain line. If the overflow pan fills up with water, the water can overflow and cause extensive damage, all of which could have been prevented. A shut-off switch can be attached to the overflow pan so that if water fills up the pan, it will shut off the A/C and stop the production of condensation. Ask your A/C service company about that it you don’t have one.
The Water Heater…
A water heater also has two drain lines (1) the Temperature Pressure and Relief valve (“TP&R)” drain line and (2) an overflow pan and drain line. Both drains are to be connected to the exterior. I find water heaters all the time in an attic that are not properly connected to drains to the exterior. These are disasters waiting to happen!
The TP&R valve is an important safety feature of the water heater and should be able to open and drain water if too much pressure builds up in the water heater. The water coming out will be hot and under high pressure. The drain line must always run in a downward direction, be secure, and drain to the exterior. If the TP&R valve begins to leak, it will drip water and should be replaced. This valve should be opened at least once a year to keep from becoming stuck with sediment and is recommended to be replaced every 2-4 years.
The overflow pan under a water heater in the attic is a safeguard system in case the water heater itself begins to leak from deterioration and corrosion. The overflow pan is generally connected to a drain line that is next to the TP&R drain pipe. The water heater overflow pan must also be kept free of insulation and any other debris that can clog up the drain line. If water is ever dripping out of the water heater overflow drain, it is an indication generally that the water heater is at the end of its life and needs to be replaced. Unlike the HVAC overflow pan that can have an overflow switch that can shut off the creation of condensation, the water heater pan cannot have a shut off switch, because the water is leaking from the deteriorated water heater that will not stop until the water heater is replaced. Again, the overflow pan must be able to drain, otherwise the water will overflow into the area under the water heater and can cause extensive damage.
The primary and secondary drain of the HVAC system and the TP&R valve and overflow pan drain lines of the water heater are extremely important components of the attic system. They are very easy to check and keep clean. Doing so will help to ensure that all will be well in your attic and home. If you ever have one of these fail, you’ll have a story to tell and will likely never let it happen again. I’m hopeful that anyone reading this article will now never have it ever happen to them a first time. Keep those drains free-flowing and drain pans in good clean condition my friend.
