Choosing a Designer/Installer: Homeowner’s Guide

Tuesday, August 17, 2010

GSHP failure is most commonly caused by improper design or installation of the system, not by failure of the mechanical equipment. Choosing a designer and installer that is properly trained, has a good reputation in your area and is willing to stand behind their work with a guarantee or warranty is important. Use this guide to help you make sure that the most important part of your system, proper design and installation, is done professionally.


The sizing and design of a loopfield is crucial to the performance of the system. The loopfield is the backbone of the operation, under or over-sizing are both detrimental to efficiencies and equipment life. Under-sizing systems can lead to excessive dependence on supplemental heat and can cause early equipment failure. Over-sizing equipment will cost more at install and can lead to short cycling of pumps which will shorten equipment life.

To avoid these issues, ask the designer of your system to provide you with the specifications for your loopfield. Don’t trust rules-of-thumb or approximations, improper designs will always cost you more. We recommend making sure the installing contractor used a geothermal loopfield sizing program like LoopLink to design your system. A good designer should be able to provide you with a complete design report that justifies their choices and they should be willing to walk you through that report to ensure that you fully understand everything it says.

IGSHPA Certified Installer

As in any technical trade, the best professionals are certified by an authority. For the geothermal heating and cooling industry, that authority is the International Ground Source Heat Pump Association or IGSHPA. Geo-Connections provides training to many of the accredited installers throughout the nation through the aptly named “Accredited Geothermal Installer Course” we provide through our partners at the Heat Spring Learning Institute. Regardless of where they are trained, make sure the person you hire is on the IGSHPA list of accredited installers.

Warranties and Guarantees

A geothermal loopfield is not a cheap thing to have installed. If it isn’t completed properly, at best you won’t make the efficiencies expected and at worst, your system will operate outside the heat pump design parameters until it fails completely. To avoid being stuck with paying twice only use installers that back up their work with a warranty or guarantee.

Always ask “What kind of guarantee do you offer on your design/installation?” and “Do you have any references?” Follow up on the references and take note of how long ago their systems were installed. It is in your best interest to find a contractor with experience that stands behind their work with a written guarantee or warranty. This is a business transaction so never take their word for it-- always get the terms in writing.