Indirect Water Heaters in Missoula & Western Montana
An indirect water heater is an insulated storage tank that uses your boiler, instead of its own burner, to heat your household water. ProCare Climate installs, connects and services indirect water heaters for boiler-heated homes, multi-unit buildings and businesses in Missoula and across Western Montana. All brands. Call or text 406-546-1289, or request a free install estimate.
How an indirect water heater works
A regular tank water heater has its own gas burner or electric elements. An indirect tank doesn't. Inside the tank is a heat exchanger coil. When the tank's thermostat calls for heat, the boiler sends hot water through the coil, which warms the water in the tank. The boiler water and your drinking water never mix. The tank is treated like one more zone on the boiler, with its own control and a pump or valve.
Why boiler owners choose one
- One heat source instead of two: no separate burner to run and maintain just for hot water.
- Strong hot water supply: a boiler can usually reheat an indirect tank quickly, which helps during busy mornings.
- Fewer things to vent: the tank doesn't need its own flue, because the boiler does the heating.
- A natural partner for radiant and baseboard heat: it uses the hot-water system you already have.
Is an indirect water heater right for you?
It usually makes the most sense when:
- You already have a boiler, or you're planning to install one.
- Your boiler is in good shape and sized to handle both heating and hot water, so the house isn't short on heat during a cold snap.
- Your old water heater is near the end of its life, which is often the easiest time to switch.
- You're building new and can plan the boiler, radiant heat and indirect tank together.
If your home is heated by a forced-air furnace with no boiler, an indirect tank usually isn't the right fit, and we'll talk through other options.
Heat pumps and hot-water heat
Some heat pump setups can tie into hot-water heat and work with an indirect tank, often with the boiler kept for backup during the coldest stretches. Whether that works well depends on your equipment and house, so it's something we'd look at in person. See our heat pump page.
Installation, permits and inspections
An indirect water heater install involves the tank, piping and controls to connect it to your boiler. We size the setup to your household or building, and installing a water heater or changing a boiler system typically involves a permit. We pull permits and schedule inspections so you don't have to. See HVAC permits and inspections.
Service and warning signs
Indirect tanks are generally low-maintenance, but not no-maintenance. Call if:
- Hot water runs out faster than it used to, or takes longer to recover
- The temperature and pressure relief valve is dripping or discharging
- You see leaks at the tank fittings or the piping to the boiler
- The boiler isn't keeping up with both heat and hot water
A yearly boiler service in the fall is a good time to check the tank, its control and the pump or zone valve feeding it. See our boiler service page and indirect water heater guide.
Multi-unit and commercial buildings
Apartment buildings and commercial spaces with a central boiler can use indirect tanks too, sometimes larger tanks or more than one. We work on multi-unit boilers and commercial systems. See our multi-unit boiler guide.
Where we work
ProCare Climate serves Missoula, Lolo, Frenchtown, Stevensville, Hamilton, Polson and communities across Western Montana. Owner Jeremy Eisenmann started the company in July 2026 and has 10+ years of hands-on HVAC experience in the region. Licensed and insured, MT License #2026-MSS-CON-00293. See also our radiant floor heat guide.
Indirect Water Heater FAQ
Do I need a boiler for an indirect water heater?
Yes. An indirect tank gets its heat from a boiler or another hot-water heat source. Homes with only a forced-air furnace usually need a different type of water heater.
Can you add an indirect water heater to my existing boiler?
Often, yes, if the boiler is in good shape and can handle the added load. We'll look at your system and give you a free install estimate.
Does an indirect water heater need its own vent?
No. The tank has no burner, so it doesn't need its own flue. The boiler's venting handles combustion.
What maintenance does an indirect water heater need?
Have it checked during your yearly boiler service, keep an eye on the relief valve, and call if you notice leaks or hot water running out faster than usual.
Do you install indirect water heaters in apartment buildings?
Yes. We work on central boiler systems in multi-unit and commercial buildings, including indirect tanks.
Want more out of your boiler? Call or text 406-546-1289, any time, or request a free install estimate.