Paloma Water Heaters
PH2-28 (9.5 Series)  
Review and Buying Tips

Paloma PH2-28 tankless water heater

Paloma water heaters PH2-28 from the 9.5 series offer an efficient whole-house heating solution and provide enough hot water for up to three simultaneous applications. Check out its features and benefits.

Paloma PH2-28 tankless water heaters are the most powerful non-condensing units from this manufacturer that can give the highest water flow.

They are working with an energy efficiency of 84%, making them high-efficient appliances and Energy Star compliant.

Because of its tankless technology, PH2-28 heaters are heating water on demand and provide endless hot water continuously, only when needed. Since they don't have a storage tank but have a small and compact design, they are ideal for wall mounting.


Models review

Paloma 9.5 or PH2-28 series offers two models, both capable of using natural gas or propane.

Indoor model

PH2-28RDVSN is a direct vent tankless model that is designed for indoor installation. A direct vent model is built with the sealed combustion chamber, and it must use the venting system to move the flue gases outside. As it uses a separate pipe to bring the fresh air inside the heater, these tankless models can be installed almost anywhere inside the house. The exhaust pipe has to be made of high-temperature resistant stainless steel.

Outdoor model

PH2-28ROFN is the outdoor model with a built-in electric blower, which is strong enough to move the flue gases from the combustion chamber out.

To prevent damages to the heater's elements, both indoor and outdoor models should be prepared correctly for the long and cold winters.



Paloma water heaters PH2-28 operate between its minimum of 11,000 BTU and a maximum of 199,900 BTU. The heater adjusts its power based on the water flow, so the gas burner modulates between these two values.

Temperature range

The unit comes with the factory set maximum temperature at 120 F, which can be adjusted on the digital remote control and set between the lowest 85 F and the maximum of 140 F. Paloma gas water heaters can be converted for commercial applications so the maximum temperature can be set to higher 185 F.

For even better temperature control, there is an option to install a bath controller USC1-117, so the hot water temperature can always be on the safe side and never above 120 F.

Water flow

Paloma water heaters PH2-28 provide a maximum of 9.5 gallons per minute, but if there is a demand for more hot water, this system can be expanded by using the DUOnex cable, so two units can be connected into one. By using the multi-unit system controller, there is an option to connect up to 20 units into one system.


Another significant advantage of PH2-28 direct vent heaters is the ICAD Safety System used to optimize gas combustion while shutting down the unit in case of an increased level of carbon monoxide.

Diagnostic system

Thanks to intelligent electronics, the 95 series can increase energy efficiency, performance, and safety while providing problem diagnostics and showing it on the LCD display.

Similar tankless and condensing models:

Safety devices

  • ICAD - Incomplete Combustion Avoidance Device.
  • Film wrap overheat limiter for fire protection.
  • Anti-boil protector shuts down the water heater if there is not enough water flowing through the unit.
  • The freeze protection system uses electric heating elements.


Paloma water heaters PH2-28 come with a warranty of 12 years on the heat exchanger and five on other parts. Its longevity depends on the proper installation, maintenance, and how you solve the problems.