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Water Leaks in Fan Coil Units

Fan coil water leaks- the role of drain pans

Fan coil units, are widely used for controlling the indoor air temperatures within condo suites, especially in places like Toronto and GTA. Each condo suite has at least one of these with a lot of units having 2-3, some even have 5-6. To know how many you have just count the number of thermostats you have on your walls. A fan coil provides you with heating in the winter and cooling in the summer with most newer condo buildings providing both heating and cooling 12 months of the year, utilizing a four pipe system. Unfortunately like most things, the older this system gets the more problems will occur. The costliest and most common of all are summer water leaks.

Understanding your home's HVAC system can save you hassles and money. In this blog, we'll clarify fan coil units, explore why water leaks occur, and guide you on when to call an HVAC expert.

How Fan Coil Units Function :

Picture the fan coil unit as the lungs of your home. They breathe in your homes air through a filter and then a temperature controlled coil, then blow out that hot or cold air into your home. Your condo building provides the coils with hot water in the winter and cold water in the summer through a closed loop labyrinth of plumbing so that you can manage the temperature in your condo suite. Here's how they work:

Water Supply: Conditioned water flows through pipes that run throughout your building and branch into each fan coil unit. Depending on your buildings age, a 3-way-valve controls the water flow into the coil, ensuring precise temperature control.

Heat Exchange: The water moves through a coil inside the fan coil unit. As air from your home passes over the coil, the air picks up whatever the water temperature is inside the coil, either heating or cooling the air as needed.

Condensate Drain Pans, Hoses and Risers: When cooling, humidity and moisture are removed from the air when the hot air passes through the cold coil, creating condensation. This water drips into a drain pan below the coil and then flows over and down a drain line and finally into a shared drain riser.

Water Leaks: Causes and Effects

While an older fan coil system itself might occasionally get a pinhole leak in the coil, the most common cause of water damage regardless of the building's age comes from issues related to the condensate drain pans, lines and risers. Over time, the pan will corrode and develop holes due to prolonged moisture exposure. These corroded metal flakes and these flakes can cover the drain hole on the pan, clog a drain hose or buildup inside the drain riser. A second source of clogging material inside an aging unit is the fiberglass liner that is used to insulate the inside of the fan coil cabinet. As the unit ages this material becomes brittle and falls into the pan, the condensate water floats the fiberglass and liner material over to the drain, if the piece is big enough it will clog in the pan's drain hole. If it’s small enough it will go into the hose where it can build up with other material or be carried out into the riser where it can also build up with other material. It’s this building up of material over time that causes a ticking time bomb. Eventually too much material builds up in the pan, hose or riser and causes a costly flood.

But that’s not all!

Because older fan coils have the perfect conditions during the summer months to grow mould, white slime mould can grow in your drain pan and cause a back up either by clogging your drain pan, hose or riser.

The worst thing you can do is ignore the issue, ignoring a fan coil water leak can only lead to more significant consequences, like damaged floors, walls, and even mold growth on or behind the drywall and baseboards. Be vigilant for pooling water and take action promptly. If the condensate drain pan, hose or riser in a fan coil unit clogs, it can lead to significant issues that will result in damage to the building and or your neighbors beside and or below you.

When to Call An HVAC Expert

Water Leakage: If you see water pooling around your fan coil unit or suspect a leak, it's time to reach out to HVAC professionals. We can diagnose the problem, whether it's a damaged drain pan, blocked drain line, or another underlying issue, and suggest suitable solutions. If your building is 15 years old or younger, refurbishment services like, fan coil relining, drain pan epoxy coating, cabinet liner encapsulation, etc… are suggested. If your building is 20 years old or older a new fan coil is your best option. Not only will they eliminate almost all possibilities of drain back ups they come with all new functionality to make you comfortable.

Damaged Drain pan by water

Solutions to persistent issues

In cases of persistent water leaks and related problems, property managers should act promptly. This might involve calling HVAC experts, like GTS Services, to assess the fan coil unit(s), inspect the drain system, and recommend repairs or upgrades.

Prevention is Key

To avoid such problems, prevention is key. Regular maintenance, including cleaning with an antimicrobial solution and cleaning the condensate drain pan and hose with a vacuum, can help prevent clogs and leaks. Quarterly filter changes as the bacteria and food source for moulds buildup on the filter. Additionally, a scheduled snaking of the buildings fan coil risers especially if there are offsets will contribute to the property's overall well-being and longevity.

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FAQs: Leaking Fan Coil Solutions

Q: Why is my fan coil unit leaking water?

A: A leaking fan coil unit is often caused by issues like a damaged condensate drain pan, clogged drain hose, or riser.

Q: What to do if your fan coil is leaking?

A: If your fan coil is leaking, immediately turn off the unit and contact HVAC professionals for a thorough inspection and necessary repairs.

Q: How do you know if your fan coil is leaking?

A: Signs of a leaking fan coil include water pooling around the unit, dampness or water stains on walls, floors or ceiling (an upstairs neighbor leaking on you), and reduced cooling or heating performance. Or a splashing noise inside the fan coil when the fan initially turns on.

Q: Can a leaking fan coil be repaired?

A: Yes, a leaking fan coil can often be repaired. HVAC experts can diagnose the cause of the leak and perform the necessary fixes, such as clearing a clogged drain line.

Q: How much does it cost to fix a fan coil leak?

A: The cost of fixing a fan coil leak varies depending on the extent of the damage and the needed repairs. It's best to consult HVAC professionals for an accurate estimate.

Q: How do I know if my fan coil needs replacing?

A: If your fan coil experiences frequent leaks, has persistent performance issues, or is reaching the end of its expected 20 year lifespan, it’s probably a good time to replace the unit.

Q: How do you know if you need a new fan coil?

A: Consider replacing your fan coil if repairs are becoming more frequent and costly, your comfort has decreased or your unit is over 20 years old.

Q: How long do fan coils last?

A: Fan coils typically last around 20 years with proper maintenance. Factors such as usage, maintenance, and environmental conditions can influence their lifespan.


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