What radiant floor heating is

Radiant floors use warm water running through pipes in or under the floor to heat rooms from the ground up. The floor surface stays comfortably warm, rooms heat evenly, and there are no drafts or noisy fans.

Why Rinnai works well

• High efficiency: Modern Rinnai condensing boilers can reach efficiencies in the mid‑90% range, so more of the gas you pay for turns into useful heat.

• Low‑temperature operation: Radiant floors typically run with water around 30–55 °C, which is ideal for condensing boilers and helps keep gas use down.

• Modulating output: The boiler automatically adjusts its flame size to match the heating load, which reduces cycling and keeps room temperatures stable.

• Small size: Wall‑hung units save space in basements or utility rooms and are easy to service.

Basic system setup

A typical radiant system with a Rinnai boiler includes:

• The boiler, which heats the water.

• A primary loop and manifolds that distribute water to the different floor zones.

• Thermostats (sometimes with floor sensors) to control each zone.

• Outdoor‑reset control so the boiler lowers water temperature on mild days, improving comfort and saving energy.

For best performance, the system should be properly sized from a heat‑loss calculation, and the boiler should be set up to keep return water temperatures low enough to stay in condensing mode as much as possible.