Using drain pans to solve tankless water heater leak problems

By Scott Gregg

When a tankless water heater leaks, the water runs out of the bottom of the unit. Much of it follows the piping to the wall where it soaks sheetrock, ruins carpet, and finds its way through the holes in the structure to spaces below and floors. A tankless leak is usually around 1GPM or so. Far less than a catastrophic failure of a tank, but still a lot of water if not contained!

At one point, tankless sales had reached about 7 percent market share of all water heaters sold. However, they are now growing exponentially due to NAECA changes that are forcing people who would not have normally considered a tankless to do so. These people have old tanks in places where the new ones simply won’t fit. The cost of a new tank is now almost the same as a professional grade tankless water heater that is installed by a trained contractor. Costs of tankless have remained the same, or become less expensive, as manufacturers develop smaller or more economical products. The cost of tanks has gone up, up, up with every new code requirement over the last several years. Cost is really not a big factor now in choosing to go tankless. If you were to go online and research major brand tankless water heater costs and compare them to today’s power vented 50 gallon tanks, you would find that tankless options are less expensive in many cases and very close in the others. They are also able to out-produce them with hot water by many times, save energy, and last twice as long when installed properly by a trained professional.

The largest void left to fill is what happens when they die? Every product has a life cycle and tankless is no different. When a tank fails, a leak may be contained by a drain pan. However, if the tank suffers a catastrophic failure (as many do) the pan does little to no good and you still get a costly mess. With a tankless and a suitable drain pan, any leak in the tankless system is 100 percent contained. It is also conveyed safely away with no additional damage saving thousands of dollars in structural repairs, preventing mold issues, etc. The Insurance Institute for Business and Home Safety says that water heater failures are one of the top five sources of residential water losses. They also say that 69 percent of all failures result from slow leaks or a sudden burst, and that an average cost per incident after the deductible was paid is $4,444!

The Wall Saver drain pan for tankless water heaters is a patented product and was developed by Nick Brizendine and me, due to the extreme demand for the product we were encountering from builders, engineers, architects and inspectors. As the product matured, we were able to enter into an agreement with Camco Manufacturing, Inc. to take over manufacturing, distribution, and further development of the product. As manufacturer’s reps for one of the major brands of tankless, we were being asked constantly why no one had produced a pan for them, even though the instruction manuals called for it and many code officials were insisting on them. Inspectors were turning down projects and installations even to the point of sometimes requiring square pans on the floor several feet below. (This would do little to protect the structure from a leaking wall-mounted appliance)

Every major brand of tankless requires a drain pan if the unit is installed where a leak can cause damage to the home or building. Architects and engineers understand that when a tankless water heater reaches the end of its life it will likely leak, just like a tank. Even though the leak is substantially less than a tank, containing the water and conveying it safely away can save thousands of dollars in property damage. It was the better engineering firms that first drove demand for the product. If it is a high rise condo, it is very possible for a tankless that springs a leak to damage the unit it is in and several others, including the one below it. This risk is totally mitigated by a suitable drain pan. Engineers basically insisted that we come up with something that would protect their valuable projects from water damage.

In addition, Camco was also able to make the product in metal, which we were unable to do in a cost effective manner. Metal pans are required in many local codes that have not kept up with tankless technology and require any pan under a gas water heater be metal. (Even though everyone’s tankless water heaters are zero clearance to combustibles and don’t get hot on the outside at all.)

Older codes and many local codes do not differentiate between tank water heaters and tankless water heaters when specifying the need for a pan. Smart inspectors understand that a tankless water heater needs a drain pan just as a tank style heater does, and that the code protects the homeowner from the water damage, mold issues, etc. likely to occur when any water heater reaches the end of its life cycle. The drain line from the pan gives installers a great place to tie in condensate drains from condensing models, or drains from the vent connections, etc., which simplifies installation.

Whether it is code or not, the inspectors also knows that a product must be installed to the manufacturer’s instructions. Therefore, even if it is not code, if the product is installed in a finished area or above a finished area (like an attic installation) the pan is required by the manufacturer of the tankless water heater per their installation instructions. Inspectors were and still are turning down installations without a drain pan. That was another driving factor for The Wall Saver. All installations do not require a pan. A tankless installed in a garage, outdoors, in a mechanical room with a floor drain, or unfinished basement, would not require one. However, those installed in interior closets, attics, utility rooms, or closets adjacent to finished spaces should always have one.

The reasons a tankless water heater can leak are really the same as the tanks. Many fail prematurely due to improper installation. Having been on hundreds of trouble shooting calls, I can tell you improper venting, really bad water conditions, or pumps not applied properly can cause a failure within the first year or two. This is not to say that all tankless water heaters will have these issues. When installed properly by a good professional, a tankless water heater should last 15 to 20 years, compared to about eight to 12 years for tanks. And, many will never leak at all, just like the tanks.

When tankless water heaters first began to get popular about 10 years ago, many contractors refused to install the service valve set below the unit, instead installing only one valve on the cold side as they had with tanks before.

“It’s the way we’ve always done it,” many contractors said.

They were comfortable with the old way and in addition they simply did not want to spend the extra $50-$75 those kits cost back then. This made it nearly impossible to service the units after the fact. Now, almost every tankless installed uses some kind of service valve set. Some models even come with them in the box. The Wall Saver is just as important to the installation of a proper interior tankless job and only a fraction of the cost of those valve sets. You will see many of the larger manufacturers add The Wall Saver to their product accessories offered right along with those valves sets, pumps, venting and other accessory products in the very near future.

For more information on tankless water heaters please see the “Tankless 101” article at

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