It’s hot.  You’ve got your swamp cooler.  You know it works.  The power supply is good.  You’ve got plenty of natural air flow.  The water reservoir has water.

Well, the water reservoir had water.  Or maybe it’s something else on your swamp cooler that’s causing that leak.

Either way, what you thought was a swamp cooler ready for action and was ready to knock the heat down and make your home comfortable again, is in desperate need of some attention.

That’s right, if you’ve got a leak on your swamp cooler, it’s not going to get better on its own.  If it’s still working well enough to put out some cold air, it may not for much longer unless you address that leak.

If your swamp cooler is leaking water, let’s take a look at what’s behind the leak, and what can be done to fix it and keep your swamp cooler working.

1. Water and Your Swamp Cooler

As a swamp cooler owner, you well know part of the magic of the swamp cooler is the evaporative process involved.  Yes, that hot air evaporating cold water and blowing out cool air as final product.

Inside Of Swamp Cooler
A swamp cooler works by taking warm outside air through wet evaporative cooler pads, effectively cooling the air.

It truly is a remarkably simple process.  As long as it works.

However, with appliances comes the possibility of wear and tear, equipment damage, and, when water’s involved, leaks.

With a leaking swamp cooler, it can be minor drip or a catastrophic flood.

Okay, maybe not catastrophic.  However, there could be enough water all over the place that your swamp cooler is put out of commission for a period of time.  Probably when it’s nice and hot outside.

So, let’s take a look at where swamp coolers are likely to leak and how to fix them.

2. First Things First, Check the Water Supply

If your swamp cooler is leaking, the first thing to check is the water supply.  If your swamp cooler is a portable type that’s filled with water by hand, clearly your hand isn’t the issue.

However, if you have a swamp cooler that has a hose connection or has a supply line that’s hard-piped to the cooler, it’s time to inspect that connection.

If it’s a hose, inspect the hose for damage and cuts.  You can repair a hose but it may be just as cost-effective (and time saving) to simply replace it.  This is especially true if the hose is constantly exposed to weather and the sun.  The damage inflicted, if due to deterioration, probably will only get worse.

Also, this doesn’t have to be a garden hose.  Some units have a water hook-up similar to the tubing you’d find on a refrigerator for an ice maker or water dispenser.  The principle remains the same, though, in that it’s usually easier to replace than repair.

If the connection is hard-piped, you might be dealing with something like a pinhole leak.  These types of leaks are easily repaired.  However, if you don’t know how to repair a leak on copper or PVC piping (depending on what your unit has) a plumber can usually do it in no time at all.

Lastly, also check any valves in the supply line.  Valves form junctions so it’s not uncommon to find leaks at such junctions.

3. Inspect Your Reservoir

If a swamp cooler’s leaking, a good chance is it’s leaking somewhere in the reservoir.  This is a big reason for leaks on exterior coolers that are exposed to weather on a regular basis.


Besides the normal wear from weather, you’re also dealing with things like exterior heat and interior cool water, causing normal expansion and contraction.  Over time, seems in the reservoir can fatigue and crack, leading to leaks.

If leaks are allowed to go on for a while, small cracks become bigger cracks and small leaks become bigger leaks.

Leaks in the reservoir that are bad can often necessitate replacing the reservoir if that’s possible.  If the leaks are due to corrosion and the corrosion has spread thoroughly throughout the unit, the entire unit may need to be replaced.

However, let’s deal with small cracks.  If you discover any, they can be fixed with a product such as a cooler coating sealant.  These products are designed to not only seal the reservoirs of coolers but also inhibit corrosion, resist moisture, and protect your equipment.

Because sealant is long lasting, you shouldn’t have to apply on a regular basis.  However, it’s a good idea to do an application any time you discover an issue.  Also, inspect old sealant before the start of your hot season to make sure it’s still serviceable.

Now if you have a portable swamp cooler, you may be dealing with a removable plastic reservoir.  If you find a leak with it due to cracks, you’ll probably have to replace it based on the manufacturer’s recommendations and availability of replacement parts.

4. Check Your Drain Plug

This is a quick check and possibly the quick fix you’re looking for.  Like other areas of your cooler, corrosion and build up can cause a drain plug not to seal properly.  If the drain plug is damaged, you may only need to replace it and move on.

If, however, the area around the plug is corroded and impacted the functionality of the plug, like dealing with crack, you’ll have to clean the area around the plug and put sealant down before replacing the plug.

5. Water Pump and Distributor Lines

If you’ve got internal leaks around the water pump or with the water distributor lines, this is a good time to repair or replace the source of those leaks as well.

No, those leaks probably won’t lead to leaks outside the cooler right away.  However, if you’re getting your swamp cooler in the best shape possible and inspect all aspects of the water side of it, you should fix these types of leaks as well.

Also, if these types of leaks are due to corrosion, you definitely want to clean and fix them so that corrosion doesn’t spread to other parts of the cooler.

Lastly, it’s just good practice to find problems and fix them when you can.  It’s good for the equipment and great for your return on investment.

Swamp Cooler Water Pump Disconnected
Make sure your water pump and distribution lines are free of corrosion and dirt so that they work properly.

6. Preventing Leaks in the Future

The best way to fix a leak is to prevent one from ever happening.

Sounds great, right?  As if you can tell exactly where a leak will occur and get out in front of it like some kind of swamp cooler mystic.

No, you can’t see the future of your swamp cooler.  However, that doesn’t mean there aren’t steps you can take to ensure your swamp cooler avoids unnecessary issues that lead to leaks.

The good news is almost all the things you can do should be part of your preventative maintenance routine already.

What are they?

  • Inspect your swamp cooler on a regular basis.  This is a big one, especially before you start using it on a regular basis (i.e., taking it out of a winter storage set-up).  Besides inspecting the electrical side, you should also be checking the water side, including tubing, hoses, connections, etc.  Look for damage and deterioration that can lead to a leak or already is a leak you never noticed before.
  • Replace water components ahead of time.  Besides changing your water pads on a routine basis, you should also repair or replace other components ahead of time if any issues are detected early.  Parts go bad and if they involve water, leaks will usually occur.  Leaks let you know something’s wrong.  If you find something wrong, take care of it.
  • Don’t let water sit in your swamp cooler if it’s not in use.  Stagnate water can lead to build-up and corrosion.  Both can lead to poor equipment performance, leaks, damage, and eventually an equipment casualty that result in costly repairs or total unit replacement.
  • Clean, clean, clean.  It’s one thing to replace your water pads and clean your reservoir from time to time.  It’s another to routinely clean out your water tubing, impeller screen, and chase down corrosion and mineral deposits.  However, performing the latter will help prevent leaks if you stay on top of it.


Leaks on appliances are always a cause for concern.  With a swamp cooler, however, it could be the difference between a simple fix and having to replace your entire unit.

Therefore finding leaks and fixing them is the best policy if you want to keep your swamp cooler operational and working for you during the hottest times of the year.

That being said, not all leaks can be fixed on your own.  You’ll definitely have to weigh your ability to fix it versus calling for help from a technician.  Always use your best judgment considering how bad the leak is and where on the cooler it’s located.

Lastly, don’t forget your warranty if you have one.  You may not have to pay for any repairs out of pocket and if the unit is too far gone, a replacement option may be in the cards for you.