STAINLESS DHW & BUFFER STORAGE
Shop APOLLO stainless steel water tanks for domestic hot water storage, indirect water heating, and combined DHW and buffer systems. The current range includes an 80-gallon indirect tank and 120–250 MAX models for boilers, air-to-water heat pumps, and hydronic systems.
80-gallon indirect tank | Combined DHW + buffer | Heat-pump systems
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A stainless steel indirect water heater tank stores domestic hot water and receives heat from a separate boiler, air-to-water heat pump, or hydronic heat source through its heat-transfer design. Instead of using its own gas burner or electric element, the tank connects to the larger heating system.
The key advantage is system integration: one hydronic heat source can support space heating and domestic hot water, with the tank acting as the dedicated hot water storage point.
APOLLO stainless steel water tanks are built for domestic hot water in hydronic mechanical rooms. The DHW80 is a dedicated 80-gallon indirect tank, while the DHW MAX models combine domestic hot water storage with buffer volume for compatible air-to-water heat pump systems.
For projects with radiant floors, fan coils, hydro stations, and domestic hot water, the tank becomes one part of a full hydronic system. That is the MBTEK use case: complete mechanical-room solutions built around heating, cooling, and domestic hot water.
Tank choice depends on domestic hot water demand, heat source capacity, recovery expectations, available space, and whether the system also needs buffer volume.
80 gallon stainless indirect water heater tank for residential DHW with boilers or heat pumps.
View productCombined domestic hot water and buffer storage for space-saving heat pump system layouts.
View product130-gallon DHW plus 30-gallon buffer in a combined stainless steel tank for larger heat-pump systems.
View product140-gallon DHW plus 60-gallon buffer for larger residential or commercial heat-pump systems.
View product160-gallon DHW plus 90-gallon buffer for high-demand residential or commercial heat-pump systems.
View productA dedicated domestic hot water tank stores potable hot water and receives heat from a connected boiler or heat pump through its heat-transfer design. This is the direct choice when the project mainly needs DHW storage and recovery.
A combined tank includes domestic hot water storage and hydronic buffer volume in one unit. This can reduce equipment count and help heat pump systems maintain stable flow, volume, and cycling behavior.
Choose from the APOLLO DHW80 dedicated 80-gallon indirect tank or the combined DHW-and-buffer models from DHW120 MAX through DHW250 MAX. Size a stainless steel hot water tank around real demand, not only household count. Consider number of bathrooms, shower use, fixture flow, simultaneous loads, commercial peak periods, heat source output, recovery rate, incoming water temperature, and mechanical-room space. For combined tanks, also account for hydronic system volume, required flow, and heat-pump defrost needs.
Estimate peak hot water use from showers, fixtures, laundry, kitchens, or commercial draws.
Match tank recovery expectations to boiler or air-to-water heat pump capacity and supply temperature.
For heat-pump systems, confirm the required buffer capacity and hydronic volume for stable flow, defrost cycles, and system operation.
Check tank height, diameter, service clearance, drain access, and connection layout before ordering.
Stainless steel is used for domestic hot water tanks because it resists corrosion, handles repeated heating cycles, and keeps stored water in contact with a durable inner surface. For long-term hot water storage, tank material matters as much as gallon capacity.
APOLLO DHW tanks use stainless steel 316 inner-tank construction and insulated designs to reduce heat loss. The result is a practical hot water storage tank for hydronic systems where durability, recovery, and service life matter.
A stainless steel domestic hot water tank still needs regular system checks. Follow the product manual and local code requirements, and use a qualified plumbing or heating contractor for installation and service.
Inspect water, heat-source, drain, and hydronic connections for moisture or corrosion during routine service.
Verify temperature and pressure safety components according to the manual and local code.
Monitor water chemistry where hardness, chlorides, or sediment may affect tank life or system performance.
Service pumps, controls, expansion tanks, and heat source equipment as part of the complete hydronic system.
Stainless Steel Water Tank FAQ
Direct answers about APOLLO stainless steel domestic hot water tanks, indirect water heating, current DHW and buffer models, hydronic compatibility, sizing, and maintenance.
A stainless steel indirect water heater tank stores domestic hot water and receives heat from an external boiler, air-to-water heat pump, or hydronic heat source through its heat-transfer design. It does not use its own burner like a conventional standalone gas water heater.
A standard water heater usually contains its own heat source, such as a burner or electric element. An indirect water heater tank stores domestic hot water but receives heat from separate equipment, such as a boiler or heat pump. That makes it useful in hydronic systems where one central heat source can support space heating and domestic hot water.
Yes. Stainless steel water tanks are well suited for domestic hot water because stainless steel resists corrosion, tolerates repeated heating cycles, and provides a durable storage surface for potable hot water applications. Correct installation, water quality, and maintenance still matter for long service life.
Yes. APOLLO stainless steel DHW tanks are designed for hydronic systems and can be paired with compatible boilers, heat pumps, hydro stations, pumps, controls, and distribution equipment. The heat source transfers heat to the tank, which stores domestic hot water for fixtures.
Yes. A stainless steel DHW tank can work with an air-to-water heat pump when the tank, controls, system design, heat-pump output, and required water temperature are matched. Combined DHW and buffer tanks can also add hydronic volume for systems that need stable flow and support during defrost cycles.
The current range includes the DHW80 dedicated 80-gallon indirect tank, the DHW120 MAX with 90 gallons of DHW and 30 gallons of buffer, the DHW160 MAX with 130 gallons of DHW and 30 gallons of buffer, the DHW200 MAX Commercial with 140 gallons of DHW and 60 gallons of buffer, and the DHW250 MAX with 160 gallons of DHW and 90 gallons of buffer.
Choose the tank size from peak hot water demand, number of fixtures, simultaneous use, heat source capacity, recovery rate, incoming water temperature, and available mechanical-room space. For commercial projects or heat-pump systems, a qualified contractor should confirm the DHW capacity, buffer volume, required flow, and system layout.
A combined DHW and buffer tank puts domestic hot water storage and hydronic buffer volume in one unit. This can save mechanical-room space, reduce separate tank count, and help compatible heat-pump systems maintain stable water volume, flow, and defrost support.
Maintenance includes inspecting connections, checking safety components, monitoring water quality, servicing pumps and controls, and following the product manual for any required flushing or inspection schedule. Installation and service should be handled by qualified plumbing or heating professionals.
