Hot Water Generators

Niles Steel Tank Hot Water Generators are equipped with 2 or 4 pass, single or double wall construction, U-bend heat exchangers. It can be operated by passing either steam or hot water through the coil to heat the tank contents. Large heating capacity in small spaces makes this heater particularly suitable for boiler rooms with low head room. Hot Water Generators come in vertical and horizontal configurations, bare, topcoated or jacketed and insulated. Select from our standard design or customize as needed. All tank fittings can be NPT, flanged or grooved end. Most generators are porcelain enamel (glass) or epoxy lined for potable water applications up to 180°F & 160 PSI max. For higher temperatures or special applications NST offers 316L stainless steel tank construction. These systems are designed primarily for natural convection in the tank. Heat exchangers are built with your choice of copper, stainless or copper nickel tubes. All tubesheets are 304 stainless steel unless requested otherwise.

Control Selection:

Hot Water Generator Controls are available for Water to Water and Steam to Water systems.  Regulators are available as Self-Operating, Electric or Pneumatic.  If the regulator is not specified for Self-Operating, Electric or Pneumatic, Self-Operating will be the default system.  Each control system is designed specifically for each Hot Water Generator System, please consult the factory for sizing and pricing.  Controls are shipped loose and must be assembled at the job site.  Niles Steel Tank uses Trerice regulators.


Water to Water Controls:

Pressure:______ (5 PSI min)


Gallons/ min: ______

Description of Boiler water (glycol, etc.):__________

Steam to Water Controls:

Pressure: ______

PPH (Pounds/ Hour):_______


Re-circulation Pump

Temperature and Pressure Gauge (on tank)

Air Vent (on bundle)

Vacuum Breaker (on tube Bundle)

Pressure Gauge (on controls)

High Limit Solenoid (requires high limit thermostat)

Tank Selection:

We use our standard water storage tank sizes as our base line for our hot water generators. If you are not familiar with our storage tanks, click here to see our available sizes. All Hot Water Storage tanks are built to order and are subject to our shops lead times. For proper sizing, we need the following information:

Heat Load – _____ Btu (Boiler output)

Tube Side:
  • Fluid – water/ steam
  • Inlet temperature ____F
  • Outlet temperature ____F
  • Flow Rate _____ gpm
Tank Side:
  • Tank fluid – water/ steam
  • Inlet temperature ____F
  • Outlet temperature ____F
  • Recovery Rate _____ gph