Avoid The Outdoor Sump Pump Freezing

Avoid The Outdoor Sump Pump Freezing

The purpose of a sump pump, of course, is to expel any rainwater that seeps into your home.  You may hope that water intrusion is less of an issue in the winter months, but that’s rarely the case.  Instead of rain, you’re dealing with melted snow and winter rains, of course.

Here in the midwest, we often experience a cycle of freeze, thaw, and re-freeze.  And these temperature fluctuations can cause water lines to freeze and back up. You’re probably already familiar with the concept of letting a faucet drip to keep your water pipes from freezing.  But how do you avoid ice forming in a drainage line outside?

What Happens if the Drainage Line Freezes?

The main goal of the drainage line is to discharge the waterflow far from your foundation, because otherwise, it will keep stagnated around the area of the foundation and eventually absorbed inside the crawlspace or basement thereafter.

So when that stagnated water is absorbed by the soil, that natural absorption should occur well away from the foundation.

When you install a sump pump, you also run a discharge line from the pump to the outside.  This line is what drains the water away from your home. If the drainage line freezes, the ice in it will block water from draining.  That drainage then builds up, collecting in your basement or crawl space and around the foundation. Without the ability to discharge the water, your sump pump cannot run continuously.  Eventually, the pump will be overwhelmed and burn out, the space will flood, and you find yourself in the exact situation you were trying to prevent.  

Outdoor Sump Pump Is Already Frozen

If your sump pump pipe is frozen, use portable heaters to thaw it. Don’t use a blow torch to thaw the line as you could hurt yourself or damage the house. If you can’t thaw the hose yourself, turn off the sump pump and call a professional contractor to thaw out the line.

Avoid The Outdoor Sump Pump Freezing

I have here some tips to avoid the outdoor sump pump freezing that are very actionable.

Use a sturdy PVC pipe. 

You will need to make certain the drainage line is free of dips and curves (no high or low points), as these can interfere with the natural flow of water. It’s this natural flow that allows the pipe to completely drain, even after the pump turns off.  Low points will create ‘pockets’ that can hold water and allow it to freeze. In our experience, the best way to do this is to use a 2 inch diameter pipe. Most sump pumps only require a 1 ½ inch pipe, but a larger pipe is more rigid and less like to compress or allow any dips to form. 

Keep the Water Moving

Stagnant water has the highest possibility of freezing especially when it is incredibly cold. If you let the water pool underneath your sump pump system, it is more likely to freeze. The frozen water might cause the sump pump to buckle and function indifferently. Therefore, be sure to keep the water running in the cold months. Allow the water to flow in and out of the pump to avoid unnecessary outcomes.

Water flow is not as heavy during colder months, so keep an eye on your device. If you notice water is icy and pooling inside the pit, alter the settings of your appliance. Most sump pumps can do more than their average pumping by just turning up the setting to make sure more water flows in and out. By keeping the water moving, you can keep your device from freezing and breaking.

Insulate your discharge line and your intake section.

This is a great way to make sure that water remains warm so that it can continue to move freely. Wrapping your discharge line, as well as your intake section, with insulation can prevent water from freezing and can contain leaks. It can also help keep those parts of your sump pump from being damaged by external elements.

Insulation does not need to be the same as what you use to insulate your home. Simply get what is recommended by your local hardware store. With a bit of insulation and a few zip ties, you will keep your pipes from freezing this winter.

Your goal is to ensure that the water stays warm this winter. By insulating the intake section and discharge line, you can keep the water from leaks and freezing. Quality insulation also reduces the risk of damage from external elements.

So to summarize the main concept here, you should insulate the sump pump discharge line, as well as the intake section to guard against freezing. Attach a larger diameter pipe to the end of the sump pump hose using wires and clamps, leaving air gap between the hose and the larger pipe. For a simpler fix, cover the outside pipe with hay, which is a natural insulator, and a tarp.

Do not pour automotive anti-freeze into the sump pump.

Create a Downward Slope in the Sump Pump

This is a completely above-grade solution, in opposition to a solution analyzed below that is burying the discharge line at least five inches below grade. Here we let gravity to perform the downward evacuation of the waterflow.

If you choose this above-grade solution, extend the discharge line away from the house at a downward slope. The slope doesn’t have to be steep, but rather continuous so that the water flows.

Connect a freeze-resistant hose to the end of the discharge hose. The hose should discharge water at least 20-feet away from the foundation. Use a smooth, rigid hose so that there is no place for water to accumulate.

If the pipe is properly sloped, gravity will help keep the water flowing. Standing water in the pipe is more likely to freeze.

Let gravity do all the work in your sump pump system. Give the pipes a slight slope that allows the water to flow down naturally. You can create a slide or a trench at the end of the pipeline.

The surface surrounding your foundation should slope down and away therefrom.

This is the easiest- and most natural- way to direct water flow in the right direction.  This is important for two reasons. First, because a good slope helps the water drain completely out of the line.  Second, the slope will encourage the water to continue draining away after it leaves the pipe.  You don’t want the water freezing inside the line, nor do you want it freezing just outside the line.  Either instance will block the drainage from leaving your home.

Protect the Pipes From The Outdoor Air

Your sump pump may freeze if the water pipes come in contact with the outside air. One way to avoid this is to bury the pipeline deeper in the ground while keeping a little portion of the pipes facing the daylight. Or, cover the pipes with a tarp or hay to prevent exposure from the cold temperature.

In many areas, where the land is flat, the water pipes meet the fresh air and have a tendency to freeze. This is especially true if the water flow has stopped because the water just sits in the outgoing hoses. There are many options to fix this problem. One of the easier ones is to simply bury the line deeper in the ground. Make sure that as little of the pipe as possible meets daylight. Or, if you feel like a simpler fix, cover the pipe with hay and a tarp to keep it from being frozen by the outside air.

Install a pop up drain in the yard

 At the end of your drainage line, attach a pop up drain.  Your contractor should be drilling three ½ inch holes in the bottom of the pop-up pipe as part of our installation process.  They then set the pop up drain into a small pit filled with five gallons of pea gravel. These extra holes help drain any water that might collect at the bottom, and having the water release into gravel helps disperse it more gradually.  All of this makes the water less likely to form puddles or wash out your soil in warmer weather.

Reduce The Workload By Redirecting The Waterflow

When the discharge hose begins to freeze, the motor is forced to work harder, putting it at risk of overheating and failing completely. Doing some work around the foundation of the property to direct water away from the basement lightens your sump pump’s workload, reducing the risk of it becoming blocked with frozen water.

Adjust the Distance of the Pump and Discharge Hose

Connect a freeze-resistant hose to expand the distance between the wastewater area and the sump pump. Maintain a minimum distance of 20 feet from the foundation and be sure to use a firm and smooth hose, so there is no room for the water to accumulate.

By connecting a freeze-resistant hose to the end of the discharge hose, you can increase the length of the discharge hose so that there is a greater distance between the property and the point where the waste water is flushed away. Aim for a distance of at least 20-feet away and use a smooth, rigid hose so that there is no place for water to collect.

This method can also be used when a backup pipe is connected to the pump. The backup pipe should be laid in a different direction to the main discharge hose so that it can be used if the main hose freezes.

In general terms, the farther away the better- but like in most things, moderation is key.  If your drainage line is 100 feet or longer, it will require the sump pump to work harder and shorten the life of the pump motor.

Some contractors will install a freeze guard, but this is not something we do, nor do we advise you to do it.  Freeze guards are overflow devices that attach to the drainage line as it exits the foundation.  It’s true that these allow water to escape if your drainage line freezes; but if this happens, the water will be released directly next to the foundation.  

The purpose of a drainage line is to move the water away from your home, because otherwise, it will pool around the foundation and seep back into your basement or crawl space. This cycle will keep the sump pump running continuously, processing the same water over and over without the ability to properly discharge the water at a safe distance.  Eventually, the pump will be overwhelmed and burn out, and the space will flood

Give the Sump Pump a Break

When the sump pump is forced to work hard, it can overheat and breakdown earlier than expected. To avoid this, you need to redirect the water away from the basement to lighten the load of the pump. Do some works around the property or the foundation of the sump pump where the discharge hose can easily operate.

Burying Deep The Sump Pump Discharge Line

Ensure that the sump pump discharge line outside the home is either buried in the yard, or extended out above-grade at a downward slope. The latter option, which is the above-grade positioning with a slope, is the option we studied above.

Bury the pipe at least five inches below the frost line, which is the maximum depth of ground below which the soil doesn’t freeze, in order to protect it from freezing. The section of pipe where the pipe meets the ground at the frost line and at the end of the line where the water disperses is where the pipe generally freezes.

There is a lot of the debate about this topic, but I consider that it should be buried at least five inches below grade. So this is the picture, below.

At 5′ below grade I don’t think your pump will freeze, assuming you cover the pit with plenty of rigid insulation. Don’t build the cover at the top of the pit though. Build it just above the high water line in the pit so that hopefully the cover will be below the frost line or at least close to it.

What about using heat tape? Well, heat tape can’t be submerged so wrapping the pump won’t work.

Another alternative is deicing cable. I think that deicing cable might work, and please, if any reader would like to share their experience in the comments section.

So regarding deicing cable, I would be hesitant to use it in a situation where it was constantly submerged as it is not rated for that. They also make small deicing heaters for bird baths and fish ponds that you could float in the water since keeping that water from freezing will keep the pump from freezing. Deicing cable may work ok in the discharge pipe. Though I’d first try and make the discharge pipe as large as possible – ideally 4 inch – with enough slope so that the water completely drains out by gravity.

Also bury the pipe as deep as you can. My experience is that a 2″ pipe will eventually freeze up at around 0 degrees F no matter what the slope is. My 4″ pipe has never frozen and is 160 feet long buried 2 to 3 feet underground. It has enough slope to allow the water to run out, but is not overly steep. My 2″ pipe is 2 feet long and is a straight vertical drop into the 4″ pipe. It is exposed to the air and has frozen after an extended period of 0 degree temperatures.

I would try and design it so you don’t have to use the deicing cable or only use it in extreme weather. It is expensive to operate. Also, deicing cable is decent at keeping ice from forming, but not so good at melting ice as it really doesn’t generate much heat.

Do not mentally relate the water pipes inside your property that you use for drinking water and the drainage line outside your home, because it is as you know, a completely different piing environment.

There’s a key difference between the water pipes running inside your home and a drainage line outside your home.  The water lines inside your home need to be buried deeper underground because they hold water all the time. They have to, because when you turn on the tap, you expect water to flow immediately.

On the other hand, a properly installed discharge line only has water in it while the sump pump is running.  When the pump expels the water from your home, it’s at a warmer temperature than the soil outside, and it’s moving quickly.  This, combined with a good slope and well-installed drainage line, should be enough to keep it from freezing before it’s cleared the drainage area.

Preventive Maintenance To Avoid The Outdoor Sump Pump Freezing

Periodically check your sump basin and test the sump pump to ensure it’s working properly. If you have a flex discharge line, make sure it’s clear of debris, snow, and ice. Also ensure that your sump pump doesn’t discharge water onto your sidewalk and driveway to prevent dangerous ice.

To test the sump pump, you could follow the following methodology

  • Locate the exit pipe that drains out water from the pump outside your home. Inspect the pipe and make sure it’s not clogged with dirt or debris. Also, make sure it directs water away from your home’s foundation.
  • Go to your sump pump, which is usually installed in the basement or crawlspace, near the walls of the foundation. Remove the lid (if it has one) and remove any debris you find to ensure the pump will not clog.
  • The first way to test the sump pump is to trace the two electrical cords of the sump pump. The pump cord plugs into the back of the float cord plug. Unplug both cords, then plug only the pump cord into the outlet. The pump should turn on immediately. If you hear a humming sound, the pump works. Plug the two cords back as they were (the float cord first, then the pump cord into the back of float plug). Not all sump pumps have two cords, and if yours doesn’t, use the methods below.
    • Pour approximately 5 gallons of water into the pump pit at a slow pace until you see the float rise. At this point, the pump should kick on. Make sure to watch as the water gets pumped out and the pump turns itself off when it pumped all the water. Repeat the test to ensure the pump works.
    • If pouring water into the sump pump is not an option, lift the float with your hand and check that the pump turns on. However, don’t let the pump run for more than a few seconds to prevent damage to the pump motor.

Causes For The Outdoor Sump Pump Freezing

The most common cause for discharge lines to freeze up is that the discharge pipe is connected to a small hose laid across the ground. 

Many homeowners think that a 2” line that is the same size as the discharge pipe is fine for moving water away from the house.  They are cheap, flexible and can be run 20-30 feet away from the foundation.  The problem is, these lines freeze up quickly because of the longer distance and, commonly, lack of proper pitch. 

What starts off as a 2” pipe will soon shrink every time the pump runs, adding another layer of ice inside the pipe.  The colder it gets the faster the line freezes shut.  Once the sump pump cannot get water out, it can start leaking out of a loose fitting or blow out altogether. 

You might come back home and find a basement full of water, ruining everything.  If you don’t get a leak or blowout, the pump will likely burn itself out because it is trying to pump water and it cannot.  Once it’s burned out, you will have water in your basement if you don’t have a battery backup sump system acting as a secondary pump. 

Sump pumps are used where basement flooding happens regularly and to solve dampness where the water table is above the foundation of a home. Sump pumps send water away from a house to any place where it is no longer problematic, such as a municipal storm drain or a dry well.

Pumps may discharge to the sanitary sewer in older installations. Once considered acceptable, this practice may now violate the plumbing codes or municipal bylaws, because it can overwhelm the municipal sewage treatment system.

Municipalities urge homeowners to disconnect and reroute sump pump discharge away from sanitary sewers. Fines may be imposed for noncompliance.

As you have read from the comments coming from many readers in different articles, many homeowners have inherited their sump pump configurations and do not realize that the pump discharges into the sewer and that currently this practice is generally “out of code”.

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BY M. Kogan

Hello, I am Marcio. I am an architect and designer, alma mater is Mackenzie. Retired in theory, but an architect never retires completely. Along with architectural projects, I am a filmmaker and have completed some short documentaries. Filmmaking and design are my passions. In HomeQN I write about home decoration and foundations. The goal is to teach homeowners to DYI as much as possible, and when this is not possible, enable them through knowledge, to evaluate service quotations and choose the best service technicians.

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