What Is an Indirect Water Heater?
An indirect water heater is a super-insulated storage tank that uses your boiler as the heat source to make domestic hot water. Instead of burning gas or using an electric element, the tank has a heat exchanger coil connected to your boiler—letting your boiler do double duty: heating your home and your water. It’s a highly efficient system for homes with hydronic heating, delivering plenty of hot water without a separate heater.
How Indirect Water Heaters Work
When you turn on a hot tap, cold water fills the indirect tank. Your boiler sends heated water through a coil or zone inside the tank, quickly warming the domestic water for use. Think of it as a powerful, energy-efficient combination—your boiler becomes the engine for both home heat and hot water supply. No extra gas line or flue needed for the tank itself.
Benefits of Indirect-Fired Water Heaters
Exceptional Efficiency
If your boiler is already running (especially in winter), making hot water this way is highly efficient—often more so than a standalone heater.
High Recovery & Supply
Indirect tanks heat quickly using the boiler’s output—ideal for big families, large tubs, or homes needing lots of hot water fast.
Long Lifespan
With no burner inside, indirect tanks are less stressed and can last 20+ years with proper maintenance.
Simplified Maintenance
Only one burner to service (the boiler’s). Indirect tanks have few moving parts and are low-maintenance.
No Standalone Fuel Source
No need for a separate gas or electric hookup—your boiler does all the work.
When Does an Indirect Water Heater Make Sense?
Indirect water heaters are perfect for homes with a hydronic boiler (radiant in-floor heating, baseboard radiators, or high-efficiency boilers). If your home uses forced-air (furnace), indirect isn’t an option. Not sure what you have? Call us and we’ll walk you through your options.
Our Indirect Water Heater Services
Installation & Upgrades
Want more hot water from your boiler? We install indirect tanks as upgrades or new zones—giving you rapid recovery and plenty of supply. Great for replacing old standalone water heaters in homes with boilers.
Replacement
If your indirect tank is aging, leaking, or its coil is failing, we’ll recommend and install a new, compatible model—sized for your needs and properly integrated with your boiler controls.
Maintenance & Troubleshooting
Low hot water? Rust? Odd noises? We service indirect tanks and the hydronic systems that support them—checking aquastats, valves, boiler temps, and more. With our hydronics expertise, we find and fix issues quickly—never just “replace and see.”
Fix Leaks, Clogs, and Plumbing Worries Fast
Call Your Local Kalispell Plumber
Is your toilet running or dripping driving you up the wall? Got a leak, slow drain, or low water pressure? No matter the problem, Modern Plumbing & Heating handles every repair—big or small—with prompt, professional service you can trust. Our licensed plumbers diagnose the real issue and fix it right the first time, saving you money by repairing whenever possible and never pushing unnecessary replacements.
Common Plumbing Repairs
What We Handle Every Day
We handle every part of your home’s plumbing system with the same care we’d give our own. Whether it’s repairing a leaking pipe, installing a new fixture, or updating your water heater, our goal is to make every job simple, stress-free, and built to last. As longtime locals, we understand what Myrtle Beach homes need and always deliver quality work backed by genuine customer care.
Leaks & Burst Pipes
Even a tiny leak can waste hundreds of gallons and lead to costly water damage. From pinholes in copper to burst pipes or stubborn drips, we find and fix leaks quickly—using quality parts for repairs that last.
Clogged or Slow Drains
Minor clogs and slow drains can become major headaches if ignored. We clear blockages from sinks, showers, and main lines with the right tools—preventing backups and further damage.
Toilet & Fixture Repairs
Running toilets, leaking faucets, broken shower valves—we fix all makes and models. A running toilet isn’t just annoying; it can waste thousands of gallons, so call us for quick, reliable repairs that save water and stress.
Water Heater Troubles
If your water heater’s leaking or not delivering hot water, we troubleshoot the real problem and repair if possible—only recommending replacement when absolutely necessary.
Low Water Pressure & Other Issues
Sudden drops in water pressure, strange noises, or smelly water? We track down the source—whether it’s mineral buildup, failing components, or hidden leaks—so your system runs smoothly again.
Sump Pumps & Specialty Repairs
From replacing failed sump pumps to fixing odd plumbing quirks in Flathead Valley homes, our team is equipped for unique challenges—old farmhouses, new condos, and everything in between.
Why Choose Modern Plumbing & Heating for Indirect Water Heaters?
Hydronic and boiler system experts—few local plumbers match our experience
Skilled at both plumbing and heating integration—one call solves both
Honest guidance: we evaluate your boiler’s condition and recommend the best hot water solution for your home
Professional installations and upgrades—always to code, with correct controls and priorities set for comfort and safety
Responsive maintenance and repairs—restoring peak hot water performance
Indirect Water Heater FAQs
Kalispell & Flathead Valley
How does an indirect water heater work?
It uses your boiler’s hot water, circulated through a heat exchanger coil inside the tank, to heat your home’s domestic water.
Benefits of indirect water heater with boiler?
Efficiency (especially in winter), high hot water output, and longer lifespan—plus one heat source to maintain.
Can my boiler also heat domestic hot water?
Yes—if you have a hydronic boiler, we can typically add an indirect tank as a new zone for hot water.
Indirect vs direct water heater—what’s the difference?
Direct water heaters have their own burners/elements; indirect tanks use your boiler for heating, requiring less fuel and maintenance.
What’s a “Boilermate” or combination boiler water heater?
“Boilermate” is a popular brand; a combination boiler provides both heat and hot water, often via an indirect tank setup. We install and service all major types.
Maximize Your Boiler
Get Hot Water the Efficient Way
Considering an indirect tank or need yours serviced? Trust the hydronic heating experts at Modern Plumbing & Heating to maximize your system’s hot water output.