Articles by John Siegenthaler, P.E.

The piping strapped to the bottom of the floor joists is supposedly part of a primary loop.

An installer is asked to use a pellet-fired boiler to supply heat to two zones of low-temperature radiant floor panels. The system includes a three-way motorized mixing valve to reduce the supply water temperature to the distribution circuits.

A heating contractor who’s trying out his first wall-mounted mod/con boiler installs it as shown above. When buying the boiler, the contractor was told to use a pair of closely spaced tees to separate the boiler and distribution system.

A designer needs to tie in an indirect water heater to a multiple boiler system. He selects a hydraulic separator for the project and connects the piping of the indirect water heater on the same side as the boilers.

The designer’s intent was to supply a low-temperature floor-heating zone, as well as a higher-temperature baseboard zone and air handler, from a thermal storage tank heated by a pellet-fueled boiler.