Don't Get Burned When Switching to a Tankless System

What You Need to Know Before Switching From a Tank to a Tankless Water Heater

Switching from tank to tankless what to know comes down to a handful of key decisions — and getting them right before installation day saves you time, money, and frustration.

Here's a quick overview of what to expect:

1. Understand how tankless works — Instead of storing hot water, a tankless unit heats water on demand through a heat exchanger. No storage tank means no standby heat loss.
2. Check your infrastructure — Gas tankless units need larger gas lines and proper venting. Electric models may require a panel upgrade.
3. Size it correctly — Calculate your peak hot water demand in gallons per minute (GPM) before choosing a unit.
4. Budget for the full conversion — The unit itself is just one part. Factor in installation, venting, gas or electrical upgrades, and permitting.
5. Know the long-term payoff — Tankless units last 20 or more years compared to 8–12 years for most tank heaters, and they're 24%–34% more energy efficient for average households.
6. Plan for maintenance — Hard water areas require annual flushing and descaling to protect the heat exchanger.
7. Pull the permits — Every water heater installation in Washington State requires a permit. Don't skip this step.

If your current tank is aging, your energy bills are climbing, or you're tired of running out of hot water mid-shower, switching to a tankless system is worth a serious look. But it's not a simple swap — it's a home infrastructure upgrade that requires careful planning.

That's especially true here on Washington's Olympic Peninsula, where homes vary widely in age, plumbing setup, and water quality. What works in a newer Silverdale home may need a completely different approach in an older Bremerton house.

I'm Ernie Bogue, co-owner of West Sound Comfort Systems, and I've been working in the plumbing and heating trades since the late 1980s — long enough to have seen every variation of tank-to-tankless conversion you can imagine. In this guide, I'll walk you through everything about switching from tank to tankless what to know, so you can make a confident, informed decision for your home.

Switching from tank to tankless: what to know before you start in Kitsap County

Making the jump to an on-demand system is a popular choice for homeowners in Kitsap County, and for good reason. The most immediate benefit is the elimination of "standby loss." Traditional tanks sit in your garage or closet, constantly reheating 40 to 80 gallons of water just in case you need it. A tankless unit only fires up when you turn on a tap.

When considering a Water Heater Replacement, the longevity of the system is a major selling point. While a standard tank usually starts showing its age around the 10-year mark, a well-maintained tankless unit can easily last 20 years or more. Furthermore, because these units are roughly the size of a carry-on suitcase and mount to the wall, many of our neighbors in places like Kingston and Indianola use the switch to reclaim valuable floor space in their utility rooms or basements.

Key technical factors when switching from tank to tankless what to know

To get the performance you expect, you have to look past the brand name and focus on the technical specs. The two most important numbers are Flow Rate (GPM) and Temperature Rise.

• Flow Rate: Measured in Gallons Per Minute (GPM), this tells you how much hot water the unit can produce at once. If you want to run a shower (2.0 GPM) and the dishwasher (1.5 GPM) simultaneously, you need a unit rated for at least 3.5 GPM.
• Temperature Rise: This is the difference between the cold water coming into your house and your desired hot water temperature. In the Pacific Northwest, our groundwater is quite cold, especially in the winter. We often need a "rise" of 70 degrees or more to reach a comfortable 120°F.
• Efficiency Ratings: Look for the Uniform Energy Factor (UEF). Modern tankless units often boast UEF ratings of 0.94 or higher, meaning 94% of the energy used goes directly into heating the water.

Common mistakes when switching from tank to tankless what to know

We’ve seen a few "DIY-gone-wrong" scenarios over the years. The most frequent mistake is undersizing the unit. A unit that works perfectly in a warm climate like Arizona will struggle to keep up with a family of four during a chilly Port Angeles winter.

Another common pitfall is ignoring the gas lines. A tankless unit requires a massive burst of energy the moment it turns on—often 150,000 to 199,000 BTUs. Your old tank likely only needed about 40,000 BTUs. If your gas line is too small, the unit will starve for fuel and fail to reach the set temperature. Finally, skipping the annual flush is a recipe for disaster. Without it, calcium and magnesium will "bake" onto the heat exchanger, eventually causing the unit to overheat and fail prematurely.

I think my water heater is on its last legs. Should I switch to tankless in Port Orchard?

If you’ve noticed a puddle around the base of your heater or your morning shower is turning lukewarm faster than it used to, you are likely asking: Is Your Water Heater on Its Last Legs? In Port Orchard, where many homes feature older plumbing, tank failure is a real concern.

Traditional tanks suffer from internal corrosion. Inside every tank is an "anode rod" designed to attract corrosive elements so the tank doesn't rust. Once that rod is depleted, the tank is next. Nearly 75% of tank heaters eventually burst or leak, which can spill 30 to 80 gallons of rusty water into your home. The average water heater flood causes between $4,000 and $10,000 in damage.

Switching to tankless eliminates this flood risk because there is no massive reservoir to burst. If your tank is over 10 years old, or if you see "rusty" water when you first turn on the tap, it’s the perfect time to evaluate a tankless conversion before an emergency forces your hand.

What infrastructure upgrades are needed for a tankless unit in Bremerton?

Bremerton has a wonderful mix of historic homes and modern builds, but older homes often require specific upgrades to handle modern tankless technology. When we perform Water Heater Repair Bremerton WA, we always check the existing infrastructure first.

1. Gas Line Diameter: Most older tanks use a 1/2-inch gas line. A high-output tankless unit often requires a 3/4-inch or even a 1-inch line to provide enough BTUs for on-demand heating.
2. Venting Requirements: You cannot simply vent a tankless unit into your old chimney or standard B-vent. Modern condensing units produce acidic exhaust that is relatively cool, meaning we use specialized PVC or stainless steel venting to safely move those gases outside.
3. Electrical Supply: Even gas units need electricity to power the digital display and ignition. However, if you are switching to an all-electric tankless unit, you will likely need a significant upgrade to your circuit breaker panel. These units often require multiple 40-amp or 60-amp breakers and a 240V supply, which can exceed the capacity of an older 100-amp home panel.

How do I size a tankless water heater for my family's needs?

Sizing is all about peak demand. You need to imagine the busiest 15 minutes in your household. Is someone showering while the laundry is running? That is your target GPM.

For a typical family in Sequim or Gig Harbor, a unit capable of 5 to 7 GPM is usually sufficient for two simultaneous showers. However, if you have a large soaking tub or a "rain" showerhead (which can pull 5.0 GPM on its own), you may need a larger unit or even two units piped in parallel. Remember to account for our local groundwater temperature; because our water starts at about 45°F in the winter, the heater has to work harder than it would in a southern state.

How do I maintain a tankless system in hard water areas like Mason County?

In areas like Mason County or parts of Poulsbo, "hard water" is a common issue. Hard water contains high levels of dissolved minerals like calcium. When this water is heated, the minerals solidify and create "scale" inside the heat exchanger.

Think of scale like cholesterol in an artery; it narrows the passage and makes the system work harder. To keep your system running efficiently, we recommend Water Heater Repair Poulsbo WA services that include an annual flushing.

During a flush, we circulate a food-grade descaling solution through the unit for about an hour to dissolve mineral buildup. If your water is particularly hard (above 7 grains per gallon), we strongly suggest installing a water softener. This protects not just your new water heater, but all your appliances and fixtures from scale damage.

Common Questions About On-Demand Water Heating

Does a tankless heater provide "instant" hot water?

This is a common misconception. "Tankless" means endless hot water, but not necessarily instant. The water still has to travel from the heater to your faucet. You may also experience a "cold water sandwich"—a brief burst of cold water if you turn the shower off and then right back on. This happens because a small amount of unheated water stays in the heat exchanger during the pause. To get truly instant hot water, we can install a recirculation pump that keeps hot water moving through your pipes.

Can I switch from an electric tank to a gas tankless model?

Yes, but it is a significant conversion. We will need to run a new gas line from your meter to the heater location and create a new venting route through an exterior wall or the roof. We also have to ensure your gas meter has the capacity to handle the increased BTU load. While the initial setup is more complex, many homeowners in the Olympic Peninsula prefer gas for its higher flow rates and faster recovery times.

How long does the conversion process take?

A standard tank-to-tank swap usually takes 2 to 4 hours. A tankless conversion is more involved and typically takes 6 to 10 hours. This time includes removing the old tank, mounting the new unit, upgrading gas or electrical lines, installing the new venting system, and performing rigorous safety tests. We also handle the permitting process with the local building department to ensure everything is up to code.

Conclusion

Switching to a tankless system is one of the smartest upgrades you can make for your home's efficiency and comfort. By eliminating the risks of tank failure and providing an endless supply of hot water, you’re investing in long-term peace of mind.

At West Sound Comfort, we’ve spent over 30 years helping our neighbors across Kitsap, Pierce, Mason, Clallam, and Jefferson Counties navigate these big home decisions. Whether you’re in Bremerton, Port Townsend, or Belfair, our team is ready to provide an honest assessment of your home’s infrastructure. We stand behind our work with a 5-year warranty on parts and labor, ensuring your new system provides comfort for decades to come.

Ready to reclaim your closet space and stop worrying about cold showers? Contact us today to discuss your Water Heater Replacement options and see if a tankless system is the right fit for your family.