Login to NYSEC


De-Mystifying the Indirect Water Heater

- 5:12 pm - January 25th, 2016

Indirect water heaters have now been around for decades, but many consumers still have a lot of questions about them. Just how efficient is an indirect water heater? Wouldn’t using my boiler year-round for my hot water cost more than just using a standard water heater? Below, we’ll break down everything you need to know about the indirect water heater, and what it means to your wallet.

What is an indirect water heater? Indirect water heaters get their name from how they function: they get their heat “indirectly” from the home’s boiler via connective piping. The piping circulates hot water (usually 180-200° F) from the boiler to a heat exchanger within the water heater. The boiler water then surrounds the coils of the heat exchanger, and the result: domestic hot water.

If your home is heated by a boiler, whether it’s oil or gas, heating your domestic hot water with an indirect water heater is a cost-effective option:

  • Higher efficiency: While the average gas water heater rates between 60 to 70% efficiency, high efficiency boilers can reach 96% efficiency. When you use your boiler as a heat source to produce your hot water, your hot water efficiency equals your boiler’s efficiency, which translates to greater savings.
  • Less heat loss: Indirect water heaters are well insulated and lose very little heat during extended standby periods, which means that you won’t have to waste water waiting for it your shower to heat up. Just hop right in!
  • Better performance: While many standard water heaters fall short when hot water is needed in multiple places at once (like when the shower and dishwasher are running simultaneously), an indirect water heater is powered by the boiler, and can produce 2 to 3 times the amount of hot water as a standard water heater.
  • Long lifespan: Indirect water heater tanks are made from highly durable stainless steel to prevent corrosion and wear, and most manufacturers offer lifetime tank warranties on their models. 

But how is an indirect water heater more efficient if I now have to run my boiler year-round? Your boiler will only fire when you need the hot water. When it does fire, it’s still producing hot water at a higher efficiency rate than a typical water heater.

If you aren’t getting the efficiency or performance you expect from your existing water heater, ask your Bioheat® fuel provider about installing an indirect water, or visit our NYSEC Member List Map to find a provider in your area today.