As the season’s change, outdoor temps will fall and many parts of the nation will see daylight hours shorten. Seasonal changes over the course of the year make HVAC functions important as they work to keep homes and buildings comfortable and safe for occupancy.

The fall season is when furnaces are started-up and heating in the home typically begins. Many areas will also soon be battling blustering cold temps and heavy snowfall. OEM HVAC applications utilize customized tools to ensure equipment runs properly and efficiently at all times of the year. Here’s a look at some of the ways customized float switches can be used in HVAC applications to assist with maintenance and to improve conditions.

Condensate Float Switches

Float switches used in condensate traps and condensate overflow pans in A/C units help with removing excessive moisture. During the summer months, these systems work in overdrive to cool homes. This can cause extra liquid condensate to form during normal operation.  During winter months, a condensate line can also become clogged or freeze due to low temperatures.

Even with regular cleanings, ensuring that extra liquid coming out of the cooling system is carried away safely is critical to keep your HVAC units running optimally. To aid with the normal operation of an HVAC system a float switch can be used to monitor the condensate trap or overflow pan that can send a warning and/or shut down the system so it does not cause unnecessary damage to property, damage or cause issues to the operation of the equipment.

A condensate float switch gets the job done.

Overflow & Drain Pans

A/C systems are designed already to handle liquid condensate, they come with a drain pan to collect the liquid expected to accumulate and direct it outside of the system. Here, float switches can detect if that emptying is failing to occur before a backup causes the water to overflow back into the house resulting in water-damaged ceilings, walls, and floors. A float switch can be used to activate a condensate pump when it detects higher than normal liquid levels.

FS31 Liquid Level sensor

SMD Fluid Controls’ The FS31 liquid level sensor is a low-voltage, condensate overflow shutoff switch that can detect level changes as small as ½ an inch and can be easily bracket-mounted in a liquid vessel to or in the top of a condensate pan for level detection.

It’s not just about cooling the home. In the upcoming colder months, HVAC applications should work intelligently to also ensure continual heat and hot water are being supplied.


Another application for a custom float switch is for controlling the automatic filling of supply water for outdoor wood-burning furnaces.

These energy efficient systems use a water-to-air exchange to deliver heat and are increasingly being used by homes and businesses.

Whether you’re searching for off-the-shelf solutions like the FS31 or want to add custom designed float switch solutions to fit specialty needs, SMD Fluid Controls can work with you to create an effective and efficient option that gets the job done.


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