A tankless water heater is a device that heats the water as you use it. Unlike the traditional tank style water heaters that we are all familiar with, the Tankless system does not store heated water. When you turn on a hot faucet in the home, the flow of water through the tankless unit initiates ignition, and the heater begins to make hot water. It stops making hot water when you turn off the faucet.
There are many great reasons to have a tankless water heater installed. Small size allows you to reclaim space in your home. The tankless system is about the size of a suitcase. It is most commonly installed on the wall, which frees up floor space. Energy savings is another great reason, and ranks high on the list of positive things that a tankless brings to the home (more about that later). Dependability and long life is another trait that a tankless water heater has. All these benefits rank high on the list, but we feel the greatest benefit of all is the fact that with a tankless water heater, you will enjoy an endless supply of hot water. Although a tankless water heater is limited in the output of gallons per minute, your supply of hot water will never run out. This is especially appealing to large families who have struggled with the limited supply and recovery of a tank style water heater. We’ve seen countless large jetted/soaking bath tubs in homes that have used as expensive “storage bins”. If you have an 80 gallon tub, a 50 gallon tank won’t even begin to fill it with a usable amount of hot water.
With gas burning appliances like water heaters, furnaces, etc., their output is based on their BTU (British Thermal Unit) RATING. A standard 50 gallon gas tank water heater typically has a 40000 BTU burner, which heats about 35 gallons per hour here in our climate. A typical tankless system has a 150000 to 199900 btu burner , which will heat 4 to 5+ gallons per minute (GPM), which equates to as much as 300 gallons per hour. More powerful tankless models will heat even more. An average standard electric tank water heater can only heat about 18 gallons per hour.
When the tankless BOOM hit the USA in the early 2000’s, we really didn’t know what to expect with regards to performance. We have literally installed thousands of tankless units in the past 20 years, and we have learned a lot about how they perform in that time. Many homeowners will attest that 4 gallons per minute (GPM) is more than enough for the average home. Larger families will typically opt for the more powerful residential models, which will give them a little buffer in high demand situations. For comparison, a 4 GPM system will allow you to run 2 standard (2.5 gpm) shower heads at the same time. When you mix the hot and cold water at the shower to get a comfortable temperature, (about 103-104 degrees) you are taking 2 gallons per minute of hot water. (2 gallons hot, ½ gallon cold). The 199k BTU units will allow you a +1 GPM advantage for those high demand situations. We have asked thousands of customers over the years if they typically run two showers at the same time, and the large majority tell us while it may happen, it is rare. For this reason, we feel that a 4 or 5 gallon per minute system will work fine in the average home. If you need more than that, a multi-unit system can be designed and installed by our team.
Although electric tankless water heaters are becoming more popular, they don’t perform well here in the Pacific Northwest for the typical whole house type operation. They can work well in cabins, coffee stands, mother-in-law apartments, etc, but in an environment where multiple users may be using hot water at the same time, they will not do well. The culprit here in the Pacific Northwest is our COLD INCOMING WATER TEMPERATURE. Tankless performance is based on “Degree of Rise”, or how many degrees the unit must heat the water to hit the target temperature. It isn’t uncommon to see incoming water temperatures in the mid 40’s in the middle of winter here in the Pacific Northwest. That means we must raise the temperature of the water 75 degrees to get to our target of 120 degrees. This performance rule applies to both gas and electric tankless water heaters. Gas fired models are powerful enough to overcome this great temperature rise and still produce 4-5 GPM. The best an electric tankless can do here in our climate is about 3 GPM. ADDITIONALLY, the average home will not have the power available for an electric tankless unit without having extensive electrical work done. By comparison, an average 50 gallon electric tank water heater needs one 240 volt, 30 amp circuit. The electric tankless unit that will make 3 gallons per minute here in the PNW will require THREE 240 volt, 50 amp circuits. Of the 400 or so tankless water heaters we install each year, only 4 or 5 will be electric models. Electric tankless models do work well in warmer climates, like the southern states and tropical areas. When we do recommend electric tankless, we ALWAYS recommend the Stiebel Eltron line of water heaters.
Tankless water heaters are commonly referred to as “Instantaneous” or “On Demand” water heaters. These names tend to insinuate that when you open the faucet, the hot water will be there “instantaneously”. However, just like with your tank style water heater, the hot water must travel through the pipes, whatever the distance is, before it comes out the open faucet. From the time you turn on the faucet, it takes about 3-4 seconds before the unit ignites and begins sending hot water into the pipes leading to the open faucet, then you have your normal wait time to get the water there. Sometimes we end up relocating the tankless system, which helps shorten the distance, and thereby the time it takes to get hot water to your faucets. There are also newer models that have built in recirculation capabilities, which can provide hot water almost instantly.
Absolutely YES. There are several ways to accomplish recirculation with tankless. Some homes have a ‘Third Line”, where a water line has been routed from the farthest hot fixture in the home back to the water heater. There are tankless models that have a pump and controls built in, that will accommodate this “third line” style of recirculation. But what if your home doesn’t have a third line? We have options for you too! There are tankless models that use the existing hot and cold lines to accomplish “recirculation”. We call this “Cross Over Recirculation”. With Cross Over recirc, there is a small bypass valve that is installed under a sink at the farthest or most appropriate location. This valve works with an onboard pump in the tankless unit to provide hot water instantly at those far away faucets during the times of day you designate. Some models even have a “smart mode”, that learns your patterns and adjusts the recirc function automatically. However, while reducing wait time is convenient, it comes at a cost. The recirculating models are more expensive to buy, and they reduce the overall efficiency of the tankless unit. They also shorten the life expectancy of the water heater, which in turn affects the warranty. Give us a call if you would like to discuss whether a recirculating style tankless unit is right for you.
Water quality has everything to do with the type and frequency of preventative maintenance required for your tankless system. For the most part, the Puget Sound region has some of the best water in the nation. Homes served by a city water supply have little sediment, or hard particles to worry about. With that said, when you look in the owners Use and Care Manual for your unit, you’ll see that they recommend descaling the unit annually or sooner. While there is certainly nothing wrong with descaling annually, we have found that customers with mid efficiency units on a city water supply should descale every 3 years. If you have a condensing unit with a stainless steel heat exchanger, it’s more like every 5 years. HOWEVER, if you are on a private well, or a community well in an outlying area where water quality may be marginal, then you should plan on an annual descaling. WHAT IS DESCALING? Descaling is the act of cleaning the heat exchanger and internal piping with a solution. We typically use distilled white vinegar, but other solutions can also be used. A small pump, a 5 gallon bucket, and hoses are used and the solution is allowed to circulate through the tankless piping and heat exchanger for about an hour. This process dissolves and washes away any hard particles that have started to cling to the inner walls of the piping and heat exchanger. We offer the service, which also includes a general checkup of the unit. We also have an instructional video linked to our website that will walk you through the steps if you prefer to do your own servicing.
In most cases they can. However, a tankless water heater CANNOT use the existing metal vent that your current gas tank style water heater uses. Although we can vent a tankless water heater through the roof, the preferred method is through the sidewall. Newer condensing models use inexpensive PVC pipe for the vents, and it’s rare that we can’t find a pathway to run the venting to the exterior. There are also EXTERIOR mount tankless water heaters. These are still popular when there are space limitations, but they have become less popular in recent years due to the great options we have with condensing technology units.
It’s all about efficiency. A non-condensing or Mid-Efficiency unit will have an efficiency rating in the 82-83% range. These units also use a proprietary type of venting, usually in the concentric configuration (a pipe within a pipe). This mid efficiency type venting will come in stainless steel, aluminum or a combination of materials. We typically limit venting to about 10’ on mid efficiency units, not only for performance, but also to control the cost. Condensing tankless units have an efficiency rating of 96-98%. Because of the higher efficiency, condensing units are able to use typical schedule 40 PVC pipe for venting. PVC pipe is typically much cheaper to install, and can be installed at much longer lengths. When considering between condensing and non-condensing units, the venting distance will oftentimes be the deciding factor. Condensing units will produce more hot water due to the efficiency advantage. As the name indicates, condensing units create condensation, which must be drained to a suitable location.
This is generally the NUMBER ONE question from people inquiring about tankless water heaters. The price will vary by brand, model, Efficiency Rating, and ease of installation. It is our experience that the average price will fall somewhere between *$5500 and $6500 plus tax for an average condensing system, and about $4200/4800 for mid efficiency units. Although these prices are 2-3 times more than the cost of the average professionally installed tank style gas water heater, you must look at all the facts before you rush to conclusions about the price of a tankless water heater. (*as of Feb 2025)
Cost to service. Standard tank style water heaters will typically be cheaper to maintain than the more complex tankless system. It will also be easier to find qualified technicians who know how to service a tank style water heater. Tankless units are much more complex, and therefore there are fewer skilled technicians available that are trained and qualified to perform maintenance and repair services.
Next to “Price”, this is the second most asked question. Energy savings is one of those difficult things to calculate. Each home will see a different level of cost to operate a tankless water heater. Family size, habits, age of family members, and other factors will dictate the amount of savings, or in some cases additional costs associated with operating a tankless system. ADDITIONAL COST? You won’t read about that in a tankless brochure. At Washington Water Heaters, we believe that honesty is the best approach, even if the truth isn’t always what a customer wants to hear. That is why you will hear us tell customers that a tankless system could actually INCREASE your operating costs. The simple reason for this is because with tankless, now you have an UNLIMITED supply of hot water, so you could very likely USE MORE HOT WATER than you normally would. However, if your habits don’t change, the average home that uses a natural gas tank style water heater should see a 30% reduction in their hot water costs. Figure on a 50% savings for those using propane gas tank style water heater, and 60% for those using a standard electric tank style water heater. We’re pretty sure energy prices will be going UP in the future, which will compound the savings in an upward fashion.
We sell ALL the brands on the market today. Any number of factors will help dictate which brand and model of tankless water heater is going to be best for your home. For instance, we will look hard at the layout of the home and where the existing water heater sits. Your needs and budget will also factor into a recommended brand. We like to find the right brand and model for your home rather than “force” a particular brand in just because that is the heater we stock. Brand has nothing to do with our profit, so we have no reason to steer you one way or another EXCEPT in how it will affect you and your family. With that said, and if all things are equal, the NAVIEN, RINNAI, and NORITZ lines are our FAVORITES. Navien is very versatile and can work where other brands simply won’t. Navien also pioneered and simplified recirculation with tankless. Rinnai units have been the #1 brand in the USA for many years, and they have recently invested millions of dollars in their new manufacturing factory in Georgia. Noritz is the #1 tankless manufacturer in the world, and they have been doing it longer than any other company (more than 60 years). When you have a very simple “through wall” vent type application, it’s hard to beat the simplicity and reliability of the mid efficiency Noritz line. They also have the EZ series of condensing tankless water heaters, that was designed to make conversion EASY!
Yes, 120 volts of power is required to run the common mid and high efficiency gas fired tankless units. Power is required for the electronic ignitor, exhaust fan, freeze protection, etc. Although losing power is rare, we do recommend that every tankless owner purchase and install a simple Battery Backup device and plug the tankless power into it. These battery backups are typically used with computers and will run a tankless water heater for 20-40 minutes in the event of a power outage. They also protect the tankless water heater from power surges. The biggest reason for the battery backup, however, is to ensure you don’t lose hot water if you happen to be IN the shower when the power goes out. There are no battery backup devices that will run an electric tankless water heater.
This is a typical question that we see. Tankless manufacturer’s always list their Gallons Per Minute (GPM) rating based on the best case scenario. They have no way to know where the tankless unit will end up. In warmer climates, ground water temperature is much higher than we have here in the Pacific Northwest. Let’s use San Diego as an example, where they enjoy a year round average groundwater temperature of 72 degrees. We typically use our hot water at around 120 degrees, so in San Diego, the water heater only has to increase the water temperature by 48 degrees to reach the target temp. Now let’s look at Seattle. Our average groundwater temp is 50 degrees. In order to raise the temp up to 120 degrees, we need a rise of 70 degrees. This means the same tankless unit in Seattle will work much harder to produce the target temp of 120 degrees. It is important to understand this issue, as many of our competitors either don’t understand this, or they are simply being dishonest. Every manufacturer publishes a performance chart for their water heaters. All one needs to do is look at the target temp, and the degree of rise to find out the gallons per minute. (120/70). As a rule, we use a 75 degree rise when quoting performance here in the Pacific Northwest, because we would rather under promise and over perform. THE GOOD NEWS IS… a 5 gpm system is more than adequate for the typical home here in our region. This unit will allow you to run 2 standard showers at the same time. Oftentimes the limitations of the piping in your home will be the deciding factor, not the output of the tankless unit.
This “buzzword” was used a lot more in the early days of tankless, and not so much anymore. This term is used to describe what can happen with a tankless water heater when you turn the hot water on and off frequently. As we learned earlier, it takes about 3-4 seconds from the time you turn on a faucet before the tankless heater is actually on and making hot water. This is due to the sequence of ignition, and then the time it takes to send the water through the heat exchanger and out into the pipes. Now with this knowledge, let’s take a look at a scenario where you may experience the CWS. Let’s say you are in the shower enjoying the endless hot water. For whatever reason, you decide to turn off the hot water (maybe you have to “scamper” out and grab a bar of soap…?) Anyway, the water is off for 15 seconds and then you turn it back on and resume your shower. Just like when you started your shower, the water heater has to go through the 3-4 second ignition and startup again, which introduced 3-4 seconds of cold water in between the previously heated water, and the current hot water flow that is heading your way. Depending on how far the water heater is to the shower, at some point you will feel that 3-4 second cool down until it clears the line. Although you will definitely feel a cool down in water temperature, it doesn’t go completely ice cold as some would have you believe (like tank manufacturers…). In reality, it is nothing more than a slight nuisance that is greatly outweighed by benefits of tankless.
The short answer is probably not. Allow us to clarify. We are more than willing to sell you a tankless water heater in a box. Can you install it yourself? Most cannot. The actual act of mounting and connecting a tankless water heater isn’t the hard part in the whole tankless equation. That is simple plumbing, and anyone with basic knowledge of plumbing practices, and who has basic plumbing tools, can get that part of the project done. The hard part of a tankless retrofit is knowing how to size the system, where to install it, how to vent it, and what to expect performance wise based on the choices you have before you. We also have to determine if the current gas meter is of sufficient size to handle the added BTU load that a tankless will bring, and many other factors must be considered before a positive endorsement can be made for switching to tankless. There are also many specialized parts and tools required for this kind of work. Tankless water heater installation is a “Specialty Niche” of the plumbing trade. A contractor that specializes in tankless water heaters (like Washington Water Heaters) is very much a specialist. I can’t tell you how many times we get the call to go fix a newly installed tankless water heater that a plumber just installed. Since we do the majority of the service and warranty repairs in the Puget Sound, we get these calls from the manufacturer’s representatives. We arrive and in most cases quickly see that it isn’t an issue with the heater itself. It is usually an installation error, or the customer was never told what they could really expect out of the system from the start. This scenario doesn’t necessarily mean the original plumber is incompetent. It simply shows that this plumber doesn’t do enough of them to really become familiar with all the do’s and don’ts of tankless. It is like going to a neurosurgeon if you need an operation on your foot. A podiatrist and a neurosurgeon are both MD’s, but they don’t specialize in the same medicine. At Washington Water Heaters, we are THE plumbers who SPECIALIZE in tankless water heater system design, repair, and installation in the Puget Sound region.
Your furnace company would need to comply with two basic requirements. They must be licensed to do plumbing, AND they must employ licensed plumbers to do the work. This will rarely be the case with heating companies (ask to see their credentials BEFORE you hire them or simply go to Verify a Contractor on the Department of Labor & Industries website). In order to do plumbing work for hire in the State of Washington, the following rules apply:
Plumbing Contractors: Licensing: As of July 1, 2021, all plumbing contract work must be performed by a licensed are no longer permitted to perform plumbing work unless they obtain a plumbing contractor license.
Designated Plumber: Licensed plumbing contractors must employ a full-time individual who holds a valid journey level plumbers certificate of competency or a specialty plumber certificate appropriate for the scope of work. This individual is designated as the dedicated plumber for the company.
Individual Plumbers: Certification: Individuals must obtain a certificate of competency as a journey level or specialty plumber to perform plumbing work.
Plumbers in Washington have to accumulate a minimum of 6000 hours of OJT and then pass a very stringent test to become a licensed Plumber. Then they must perform continuing education every 2-3 years to maintain their license. By contrast, a HVAC Technician has no licensing or education requirements to do HVAC work in Washington. Don’t trust your complex tankless project to anyone who doesn’t specialize in the plumbing trade, and who isn’t licensed to do plumbing. Additionally, manufacturers have tightened down on who can install their product. All manufacturers say that to have a valid warranty, the installer MUST be a licensed plumber.
We recommend that you contact the manufacturer BEFORE you attempt to purchase a tankless water heater from an online source. In the past, manufacturers did not authorized the sale of tankless units from anyone except an approved wholesale or retail outlet. The validity of your warranty depends on this, and it is best to know upfront what you are getting yourself into.
Our sister company Kodiak Heating and Cooling will handle all your home Heating and cooling needs
Contractor# KODIAHC824LH