System Syzer is an HVAC tool that helps with piping system design. The application is based on the original plastic wheel calculator by designed by Gil Carlson of Bell & Gossett. It was first introduced in 1963 and has since been distributed to well over a hundred thousand engineers and tradesmen.

The tool is made up several different calculators. There is a calculator for friction loss and velocity through pipe based on your fluid conditions. Use it to determine the relationship between fluid temperature, system flow and heat/cooling load. There is a Cv tool that can help in multiple ways.

We have also bundled the Circuit Setter® / Triple Duty Valve calculator that is very handy for balance contractors. Use it during design to help predetermine valve settings and out in the field to determine flow through the valves based on pressure drop readings.

What’s New

Version 2.0.2

• Fix Circuit Setter bug where the "Settings" value would not reset to 0 when tapping the reset button.

Ratings and Reviews

3.7 out of 5
3 Ratings

3 Ratings

west177 ,

Good start

A nice app with all the required functions. Needs recommended flow ranges for various pipe sizes similar to the wheel.

Pat 1776 ,

B&G wheel on hand

Love this handy app! I am a NEBB BCP / TAB that works for a large mechanical contractor. I have used this app for years to communicate the GPM flushing requirements, troubleshoot issues with systems, and pre balance hydronic loops.

DevilsPoet ,

Inaccurate compared to B&G class materials

App needs work. Compared to other modern apps the interface is old slow and lacks sophistication. For example, fields must be reentered often, and auto populate with values that must be backspaces to removed.


Xylem Inc.
6 MB

Requires iOS 8.0 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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