The installer is tasked with setting up a three-zone radiant floor heating system using a 5-ton geothermal heat pump and a mod/con boiler, connected through a primary-secondary system with closely spaced tees. The system includes 4 earth loops of 1” HDPE tubing, each 500 feet long, supplying the heat pump, and features underfloor tubing with aluminum plates.

A hydronics newbie decides that he can eliminate the temperature drop effect by putting all three supply-side tees upstream of all three return-side tees. If you don’t think it will work, what would you do to change it?

An installer inspects a system where an aging steam boiler supplies several cast-iron radiators. He proposes to convert the system from steam to hot water and replace the old boiler with a mod/con boiler. Can you spot some potential problems and suggest some improvements?

An installer is asked to replace two aging cast-iron boilers with two mod/con boilers, but reuse as much of the existing distribution system as possible. Can you spot several details, omissions or other quirks that will lead to problems over the life of this system?

Can you diagnose why this glitch is happening, and suggest alternate methods for constructing this portion of the system?

Can you diagnose why this glitch is happening, and suggest alternate methods for constructing this portion of the system?

Take a look at Figures 1, 2a and 2b. What do they have in common? Can you think of some better ways to accommodate the flexible tubing?

Can you spot at least six design or installation details that are going to create problems?

Are you an ace troubleshooter? We pose a question to you, our readers, to review a system’s schematic layout and discover its faults, flaws and defects.

A recent inquiry involved a heating system for a school in which two electric boilers were being added to supplement the output of a gas-fired cast-iron boiler, and take advantage of low “off-peak” electrical rates.