What Is a Water Heater Drain Pan?

Last Updated On June 11, 2024

Updated on September 10, 2021



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what is a water heater drain pan

Without a doubt, your hot water heater is one of the most overworked and under-appreciated appliances in your household. After all, you wouldn’t be able to do laundry or take a long shower comfortably without it.

That said, there are certain elements about your unit that you need to pay attention to. For example, the drain pan. 

This crucial piece helps ensure your system is safe and that you don’t have a leaking water heater. If an incident occurs, it collects the water and prevents further damage from happening to your home.

However, most people don’t realize that their existing unit might not have a drip pan. Here is your complete guide to hot water heater drain pans including what they are, why they are important, and how to get one installed safely.

In this PlumbingNav guide, we will cover:

  • What is a water heater drain pan?
  • Why do you need a water heater drip pan?
  • Drain pan materials
  • Drain pan costs
  • Best water heater drain pans

What's In This Guide?

      What Is A Water Heater Drain Pan?

      Essentially, a water heater drain pan is a large metal container that sits under your existing unit to catch any residual leaks. But that isn’t the only name you might know them by. Some plumbing teams and professionals call them drip pans, catch trays, overflow trays, or any other variation of basically the same concept.

      Water heater drip pans sit directly beneath your unit. They generally have a hole and piping that leads to a nearby floor drain that removes excess drips from the drain line outside. 

      This ensures that any moisture doesn’t cause water damage to drywall and cause an unhealthy mold problem or create a fire hazard with electrical wiring, especially if you have an electric water heater or washing machine in the area.

      Usually, they’re round and about 24-inches in diameter with a four-inch depth for adequate water collection. Most drip pans are made from a steel core that’s plated in zinc for rust protection and overall durability, but there are some less expensive varieties made from aluminum. 

      They generally last for decades, sometimes even longer than your initial hot water heater, unless a rust problem appears.

      Reasons Why Your Water Heater Should Have a Water Heater Pan

      If you take a moment to think about the concept, your hot water heater holds hundreds of gallons of liquid throughout any given day. Should a malfunction occur causing a leak, that water has to go somewhere, and that place is inside your home. Yikes!

      Having a water heater pan ensures that any accidental liquid coming from the drain pipe is funneled to the nearest drain. This is incredibly effective for slow leaks, which is what most homeowners experience when they have a problem with their unit. Because, let’s face it, who is really keeping tabs on their water heater on a daily or weekly basis?

      If a leak goes undetected for a long period of time, the drain pan ensures that water goes where it needs to without causing damage.

      In certain states, having a drain tray under your hot water heater is a code requirement. So, even if you don’t have one right now, you might need to have one installed in order to bring your residence up to inspection requirements if you ever plan on selling.

      Hot Water Heater Drain Pan Requirements

      What requirements are there for having a hot water heater drain pan? First, we are talking about traditional storage tank units. While the requirements largely depend on the rules of the area you live in and the location it is installed, most follow a similar set of guidelines. 

      For example, if your hot water heater is in an interior room or in an attic, you are likely already required to have a drip pan. This is also true if your unit is above ground level.

      If your gas water heater is located in a garage or outbuilding, you likely have no drip pan requirement. However, it is still a good idea to have one in case of a leak, as we’ve already mentioned above.

      The type and style of your water heater drain pan is generally up to you. A galvanized steel pan is heavier and far more durable than other alternatives, and it costs the most. A metal pan made from aluminum is fine, but don’t generally last as long. 

      A plastic pan costs the least, but it will break after only a few years and need replacement. However, they won’t create rust from corrosion.

       In most cases, a licensed plumber will generally suggest a steel or aluminum pan.

      Does a Tankless Water Heater Need a Drain Pan?

      With the rise in popularity of tankless water heaters, many people want to know if they require a drain pan. The answer is yes, you’ll still need one to protect against any leaks or issues that happen when you least expect it.

      These drain pans are much like the round kind you would get for a standard hot water heater, but they are shaped just a little differently. Instead of being flat, they are much deeper and resemble a box. Tankless hot water heater drain pans also cost about double their traditional counterparts.

      did you know what is a water heater drain pan

      How Much Does it Cost to Get a Drain Pan Installed on a Hot Water Heater?

      Installing a drip pan on a hot water heater isn’t a difficult or expensive task. Depending on the type you buy, the pan can cost anywhere from $10 to $100. Why such a large swing in the price? 

      The materials and shape determine how much you’ll spend. Just remember, you get what you pay for, and this isn’t an area where you want to go by lowest price alone!

      If you’re hiring a professional plumber, the total cost of a properly installed drain pan can be anywhere from $150 to $300 or more. While the drip pan itself doesn’t add much to your bill, labor is where you’ll see the biggest expenditure. 

      Attempting to DIY this sort of project can take a full day for a novice, where hiring a professional could cut that timeframe down to a couple of hours.

      How to Install or Replace a Water Heater Drain Pan Yourself

      Installing a hot water heater drain pan generally goes like this. The existing hot water heater is unhooked from any gas, electric, or water connections. It is lifted aside and the drip pan is put in place. 

      If there’s an existing drain, it is hooked up to that. If not, then plumbing needs to be run. Then the hot water heater is repositioned in place and carefully hooked back up. Once everything is tested and works, the project is complete.

      So, what’s the big issue with trying to handle this task yourself? The problem with installing a hot water heater drip pan is that the process is super difficult to do if you’re attempting it on your own.

      Lifting the hot water heater, placing the pan, replacing the unit back where it goes, and then hooking it all back up can be difficult if you aren’t familiar with this type of job. And that doesn’t include any special drain plumbing that you might need to do. 

      Instead, it’s always better to choose a seasoned professional than risk problems that come with doing it yourself.

      What Size Drain Pan Do You Need For A Hot Water Heater?

      Choosing the right size for your water heater drain pan is simple if you remember a few key measurements. Of course, this is sometimes mandated by your local code requirements, so check those out before you head to the home improvement store.

      First, the new pan needs to be at least two inches in diameter bigger than the overall hot water heater, all the way around. Next, check for depth. Your water heater drip pan should be at least 1 1/2-inches to 2 1/2-inches deep to ensure there’s plenty of room for standing water. Finally, there should be a gasket on the side to attach drain plumbing.

      Should You Choose a Plastic Or Aluminum Water Heater Drain Pan?

      As mentioned above, you get what you pay for when it comes to choosing a hot water heater drain pan. While zinc-coated steel is always the best option, this isn’t always a choice if your local home improvement store is sold out. That’s when you’ll need to decide between plastic or aluminum. 

      With aluminum, you can trust that the catch pan is prime to stay in good condition for many years to come. Plastic offers a lower price point, but likely needs replacement much sooner. You also run the risk of more easily damaging the plastic catch basin during installation. 

      Since the process of installing a drain pan is on the difficult side, and both options are relatively inexpensive, it is usually better to go with the higher-quality aluminum drip pan option.

      How Much Water Does a Drip Pan Hold?

      In most circumstances, a hot water drain pan can hold a few gallons of water at most. Remember, this is just designed to handle small leaks, not an emptying of your entire unit. If there’s that much water spilling out, you need to call a plumber immediately before further damage occurs.

      What Are the Best Water Heater Drain Pans to Use?

      You have plenty of options when searching for the right water heater tray for your unit. Some of the more popular brand names include Camco, Eastman, and Wirth for aluminum drip trays. 

      Oatey is a very popular and highly rated plastic tray manufacturer. And the square-shaped hot water heater pans from KMG offer extra durability, as they are constructed of galvanized steel. 

      FAQs For Water Heater Drain Pan 

      How does a hot water heater drain pan work?

      A drain pan works by fitting underneath the water heater and collecting excess water from a leak. You empty the water as needed. 

      Is a hot water heater drain pan necessary?

      All storage tank water hearts can benefit from a water heater drain pan. 

      What is the purpose of a pan under a water heater?

      The pan underneath the water heater collects water from a leak. 

      Can I drain the water heater into the drain pan?

      No. Most drip pans cannot support the amount of water that comes out when you drain the water heater tank.

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      About Plumbing Navigator

      We write about "all things plumbing," helping you navigate common questions, repairs, and the best plumbing products on the market.

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      We write about “all things plumbing,” helping you navigate common questions, repairs, and the best plumbing products on the market.

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