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AC leaking water?

Prevent water damages with Strips Sensors

The hard-working AC

Processing warm air through an AC system will expel moisture as the air passes through the evaporator coils for cooling. The excess moisture drips off the evaporator coils into the drip (or drain) pan, which acts as a safety net preventing the water from coming in contact with the surrounding environment. 

A fully functioning AC installation will quickly expel the collected water from the drain pan through the drainpipe. Many issues could arise blocking this process and, in the end, damage the technology, the house structure, and items in the household.

In many cases, an AC unit is necessary for acceptable living conditions. In warm regions such as Florida, AC systems will be running 24/7 to tame the environment and bend it to human favor. 

The more your AC unit is working, the more often it will require maintenance, cleaning, and finally become worn out.

AC diagram showing cause for water leak
  1. Blower
    A fan circulates air over the evaporator, dispensing the chilled air.
  2. Evaporator
    Cooling coils remove heat and humidity from the air using a refrigerant. Condensed humidity drips down on a pan and is dispensed through a drain.
  3. Filter
    Removes particles from the air intake.
  4. Condenser
    Hot coils release the collected heat into the outside air.
  5. Compressor
    A pump that moves refrigerant between the evaporator and the condenser to chill the indoor air.
  6. Fan
    Blows air over the condenser to dissipate the heat outside.

Water leaks happen

Several conditions can lead to much higher water production and accumulation in the drip pan than usual. If water levels build up faster than the drainage system can expel, you will have an AC leaking water.

  • Condensation pumps can malfunction and start to release moisture. Such a malfunction is often a precursor to further damages to the system.
  • The evaporator coils can become frozen, most often due to too low refrigerant levels, leading to an increase in water production. Low refrigerant levels are usually a sign of leakage within the system and could become very costly in reparations if not correctly addressed.
  • A poorly installed drip pan with a tilting angle leads to water pooling before emptying through the drain pipe. It could also be the case that the drip pan does not have enough support from below, which allows it to tilt.
  • The drain pipe or the drainage system might be clogged or physically damaged so that the system does not have any means to dispel the excess water that builds up in the drip pan. Common problems can be mold and algae growth in the drainpipe or an excess accumulation of dust and dirt that has been cleansed from the air through the evaporator coils and then sent out through the drainage system.
black spots mold.web
Black spots mold

The presence of water in the drain pan is not a cause of concern in itself. When the water becomes stagnant in the drip pan, you can be sure of not working correctly. At that point, the risk of water damage is much present and is likely to be an issue within a relatively short time frame. 

When a faulty system is a fact, there is a risk of several negative consequences for the AC system and the house and its inhabitants: 

  • Bad, smelly, and even harmful air can start to circulate. Moist and moldy conditions can quickly arise, which could lead to health concerns and damage the building.
  • Expensive AC equipment can become damaged and in need of replacement.
  • Energy expenses can rise exponentially as a result of an AC system that is not running correctly.


Keep a close eye on the health of the AC system to avoid painful surprises, massive expenses, complicated insurance claims, and damaged belongings. 

The installation often comes with a float switch to turn the system off when the drip pan starts to fill up, but float switches commonly require around 1 inch, or 2,5 centimeters, of water in the pan before it reacts. For example, if you have a sloping or incorrectly installed drain pan, plenty of water can build up and start to leak before the float switch reacts.

Your plastic drain pan can also crack due to heat and start to leak, which would mean that water will never build up in the tray to a level where the float switch would notice an issue. Besides requiring a buildup of water before the controls react, float switches are often not reliable. Sometimes they alert too late when water damage is already occurring or not even reacting at all. 

A solution to these challenges is complementing the installation with a more dependable water leak sensor. By installing a water leak sensor in the drip pan placed on the side where it connects to the pan’s bottom, you can set things up to be alerted as soon as water builds up and becomes stagnant in the drip pan.

drain pan w strips

We recommend that you set up your water leak alarm so that there is a layer of material, for example, a strip of plastic, between the drip pan and the water leak sensor.

Never mount a wireless sensor on a metal surface directly. It will disturb the radio signal and reduce the transmission range and sometimes even block the signal.

If you chose an absorbing material, it would soak up the moisture from the pan’s bottom as soon as it starts to build up. By implementing a Strips Drip water leak sensor with an absorbing layer between tray and sensor, you will have the best user-friendly AC water leak alarm available.

condenser drawing with drip mounted outside

If you have a drip pan made from plastic, it has a higher risk of cracking if the surrounding temperature becomes too high. In this case, it would be highly advisable to place a sensor that can detect a leak of that type, i.e., a leak that does not result in a water buildup.

If your installation require a secondary drip pan to cover the whole setup, you can place a sensor on the second tray to detect a possible leak from the main drip pan. Alternatively, you could place a sensor on the floor under the installation to ensure that any leaking water is detected before it penetrates the construction.

The cost-saver

Damage from an AC leaking water might be one of the worst issues you face as a homeowner, and it is far from merely an uncomfortable situation. A water leak can deeply penetrate structures and cause damage that requires a lot of work and money to fix. Such damage could lead to your family not being able to even live in the house for a while. Drying out the damaged structure, or at worst, replacing it, are time-consuming and costly.

Water leaks and mold can often permeate and damage all building structures – Ceilings, walls, baseboards, insulation, flooring, and drywall. For example, replacing 200 sq.ft. of vinyl flooring can cost over $1 000, while mold remediation adds an extra $1 500 for a space that size. US national average costs for repairing water damage are estimated to around $3 000-$8 000, while AC leak damages in the UK range from between £700-£1 500. These costs can be much higher depending on service challenges in the building, the extent of damages, extra fees from the service company, etc. You may also have personal belongings destroyed that may be irreplaceable such as photos, diaries, paintings, etc.

An insurance company usually covers at least some of the related costs. Still, keeping in mind that documenting AC leaks properly, required to have insurance claims approved can be challenging and requires a service professional. An AC system is in contact with most parts of a house, and in all these areas, water leaks or moist air can start to damage the structure. It may thus be difficult to establish what has caused the damage and from where exactly the problem originated. Without proper documentation, you are at risk of having to pay for the costs yourself. Because of this, regular health checks of your AC system and adequate supervision of operations will have you ready for any situation, whether allowing you to act ahead of any accident or having proper documentation when things have gone wrong.

Do not let accidents happen; empower yourself by staying informed about the challenges that your AC system might be facing. Sensative’s easily installed Strips Drip sensors alert you when any alarming water levels start to build up or if moisture is present where it should not be before any real problems occur. By monitoring moisture and water levels in real-time through a Z-Wave Smart Home system, you will be alerted before your AC is at risk of shutting down and leaving your house in a hot mess.

In contrast to all the possible expenses, installing one or two easy-to-use and reliable sensors that cost less than $50 per unit is a very sound investment. A Strips Drip sensor from Sensative in combination with a float switch and regular system maintenance will make it very unlikely that your system will ever put you in any problematic situation or cause any damage to your home. With Sensative sensors, you can spend your time and resources on more productive things than worrying about possible water leaks or stressing out about how to pay for water damage.



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