A stainless steel indirect water heater uses heat from a separate heating system to warm stored domestic water; it is not the same as a plug-in immersion heater or a tankless unit. Of the listed products, the Triangle Smart 60 is the closest match to an indirect storage tank, while the AB side-arm exchanger is a component for transferring heat. The other options are separate electric or gas water heaters. Compare the product type and listed specifications carefully before choosing.
| Product | Best suited for | Product type |
|---|---|---|
| TRIANGLE Smart 60 | Buyers seeking an indirect-fired storage tank | Indirect storage tank |
| AB 25-inch Side Arm Heat Exchanger | Buyers evaluating a stainless steel heat-transfer component | Heat exchanger |
| 2.5-Gallon Electric Water Heater | Point-of-use hot water | Electric mini-tank |
| 1500W Immersion Water Heater | Portable, small-volume water heating | Immersion heater |
| Rheem RTG Series 7.0 GPM | On-demand propane hot water | Tankless heater |
TRIANGLE Smart 60 Indirect Fired Storage Tank
This is the closest listed match for someone specifically searching for an indirect water heater. Its product name identifies it as an indirect-fired storage tank, a category designed to store domestic hot water heated by a separate heat source. The provided listing does not include detailed construction, connection, or capacity specifications, so confirm those details before purchase.
Best for: Buyers who want to compare an indirect-fired tank with their existing heating-system setup. Why it was selected: It is the only listed product explicitly identified as an indirect-fired storage tank. Limitation: The supplied product information does not establish that the tank is stainless steel; verify the tank material and model specifications.
AB 25-Inch Side Arm Heat Exchanger
This 25-inch side-arm exchanger is listed as fin-enhanced 304 stainless steel, with 3/4-inch FNPT connections and a stated heat-transfer rate of up to 13,500 Btu per hour. The listing says it can heat up to a 27-gallon tank. It is a heat-transfer component, not a complete indirect storage water heater.
Best for: Buyers researching a stainless steel exchanger for a compatible tank arrangement. Why it was selected: It is the clearest listed match for the stainless steel and heat-transfer aspects of the search. Limitation: The listed output is a product claim, and suitability depends on the system and installation; it does not replace a complete tank.
2.5-Gallon Electric Water Heater
This 1500-watt, 110-volt mini-tank is intended for point-of-use applications such as under a sink, in a laundry area, or in an RV. Its listed features include a digital display, adjustable temperature from 86°F to 149°F, pressure-release valve, and wall-mount or countertop placement. The listing also describes connecting it in series with a larger water heater.
Best for: Buyers who need a compact electric water heater near a fixture. Why it was selected: Its small tank and installation options make it a useful comparison for localized hot-water needs. Limitation: It is an electric mini-tank, not a stainless steel indirect heater; the listing does not specify stainless tank construction.
1500W Smart Immersion Water Heater
This portable immersion heater is listed with a 304 stainless steel guard, a smart thermostat with 14 preset temperatures from 68°F to 194°F, and a display for water temperature. The listing describes automatic temperature control and shutoff protections, and names bathtubs, buckets, and pools as possible uses.
Best for: Buyers who need to warm a small volume of water temporarily rather than install a household water heater. Why it was selected: It includes a stated 304 stainless steel component and temperature controls. Limitation: The stainless steel guard does not make this an indirect storage tank; follow the product’s safety instructions for use around water and electricity.
Rheem RTG Series 7.0 GPM Tankless Heater
This outdoor liquid-propane tankless model is listed at 7.0 gallons per minute and 160,000 Btu, with a non-condensing design. It heats water on demand rather than storing hot water in an indirect tank.
Best for: Buyers comparing an on-demand propane system with a storage-based option. Why it was selected: It provides a clear alternative for readers who may be considering different water-heating approaches. Limitation: It is not an indirect water heater, and the provided information does not specify stainless steel construction.
Buying Guide: How to Choose an Indirect Water Heater
Do you need a complete tank or just an exchanger?
An indirect water heater is a storage tank heated through a separate heat source. A side-arm exchanger transfers heat but is only a component. Confirm whether the product includes the tank, exchanger, and required connections rather than assuming those parts are interchangeable.
Is the tank actually stainless steel?
Check the manufacturer’s specifications for the tank material, not only the material of a guard or heat exchanger. In this product list, the AB exchanger and immersion heater specifically mention stainless steel, but that does not establish that the Triangle tank is stainless steel.
Will it work with your heating system?
Compare the tank’s connection requirements and heat-transfer specifications with the existing system. Have a qualified installer verify suitability, sizing, and installation requirements. The supplied details do not provide enough information to confirm compatibility for any particular home.
Does a tankless or electric alternative fit better?
A point-of-use mini-tank serves a nearby fixture, while an immersion heater is for temporary small-volume heating. The Rheem listing describes an outdoor propane tankless unit. These products serve different needs from an indirect storage tank, so compare the intended use before selecting one.
Frequently Asked Questions
What is a stainless steel indirect water heater?
It is a domestic hot-water storage tank that uses heat from a separate heating system. The word “stainless steel” refers to the tank material and should be verified in the product specifications.
Is the Triangle Smart 60 confirmed to be stainless steel?
The supplied product information identifies it as an indirect-fired storage tank but does not state its construction material. Check the full manufacturer specifications to confirm.
Is a side-arm heat exchanger a complete water heater?
No. The listed AB product is a heat exchanger, not a complete storage tank. Confirm what additional equipment the system requires.
Can a tankless heater replace an indirect tank?
They use different designs: the listed tankless unit heats water on demand, while an indirect system stores water heated by a separate source. Which is suitable depends on household needs and installation requirements.
What should buyers verify before ordering?
Confirm tank material, capacity, heat-source requirements, connections, dimensions, and installation needs from the complete product documentation.