What do home inspectors look for in geothermal systems?

Taken during an inspection of a geothermal system used for heating and cooling the home, as well for producing hot water.


What is geothermal?

Wikipedia defines geothermal energy as “…thermal energy generated and stored in the Earth”, but when it comes to residential homes, it always refers to a system that uses piping in the ground to extract heat from the earth.

These systems use loop of piping that is buried outside of the home in order to extract heat from the ground, or deposit it there, depending on whether the system is in heating or cooling mode.  This “loop field” is typically installed in a series of trenches. In areas where space is at a premium or where the land is hilly or forested, one or more holes can be drilled for the piping.

Geothermal systems can be used instead of furnaces, air conditioners, boilers and domestic water heaters.  Less common uses include driveway snow melting systems or swimming pool heating applications. Two of the leaders in the residential geothermal industry in the United States are Waterfurnace and Climatemaster.

Components of geothermal heating and cooling systems always include a heat pump, ground loop and recirculation pump.  If used to heat water for drinking, bathing and other purposes your system would include at least a water storage tank.  Some water heating systems use a dedicated heat pump for heating domestic water.

Why do people use geothermal heat pumps?

If geothermal systems are sized properly, the cost to operate them can be substantial when compared to propane and heating oil.  When compared to natural gas, a system that expertly designed can present a 50% savings in heating costs over a year.  

Since geothermal heat pumps rely on electricity, if the home has a solar panel installation then the overall energy footprint of the home can be extremely low. 

Tax incentives and rebates are available to lower the cost of installation and equipment.  Here in New York state, utilities are starting to incentivize geothermal heat pump installations in line with the state’s overall goal of reducing natural gas usage. 

Is Buffalo and Western New York too cold for heat pumps to work properly

The answer to this question is “no”!  The US Department of Energy even states on their geothermal FAQ page, that “geothermal heat pumps can be used in any climate”.

Natale Builders is a custom home builder in the Buffalo area that chooses to install geothermal systems in their homes. They would not put their reputation on the line for an unproven technology.

Geothermal systems extract heat from the ground, compress it and transfer that heat into your home.  Modern geothermal heat pumps use variable speed compressors, fans and water circulation pumps, making them extremely energy efficient, even in during our frigid winters in Buffalo.

If the components are part of a design that considers the system as a whole, and the installing company knows what they are doing, then you should expect a system that works well.

Geothermal heat pumps should be designed so that do not need to use the “emergency heat” feature, which creates heat in the same way as an electric strip heater.  Heating in this way is very expensive, and should only be used if the system experiences a malfunction.  

The outside loop is critical to the performance of a geothermal system.  Proper length and diameter of the pipe are critical factors. The specific type of pipe is also important, with the industry consensus being that high-density polyethylene (HDPE) being the best in terms of resistance to damage from rocks and minerals in the ground and transfer of heat.

What should a home inspector look for when inspecting a geothermal system?

Geothermal heating and cooling systems are complex, but that doesn’t mean that Western NY home inspector should just disclaim the entire system and “pass the buck” to their client.

The service covers or panels of most geothermal systems aren’t designed to be opened by homeowners or inspectors, and so we do not open them.  But there are several items that we check and advise on:

  1. Heat pumps are checked over for physical damage
  2. Electrical breakers, connections and wiring are inspected
  3. Outside loop areas that are visible in the basement or crawlspace are checked for leaks and to ensure that they are insulated
  4. The foundation wall outside loop penetrations are inspected for adequate waterproofing and for signs of leaking
  5. Condensate overflows are inspected to ensure that they are not clogged or otherwise backed up
  6. If the outside loop is un-pressurized (as most are) open the circulation pump and check the water level
  7. If a heat pump for domestic hot water is present, we inspect the storage tank or secondary water heater.  
  8. During the heating season we turn the thermostat up a few notches and attempt to test the emergency heat feature.  We only do this briefly, and return the thermostat to its original setting after we are finished
  9. Only during the cooling season, we make sure that cool air is produced
  10. As with all home inspections, we walk through the home and test a representative sample of supply and return registers for air flow

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About the Author:

Bradley Beck

Bradley is owner of Alto Home Inspection, LLC.  He lives just south of Orchard Park, in Western New York’s Southtowns, and inspects homes throughout the Buffalo area, and is NY Licensed Home Inspector #16000086029, NY Certified Mold Assessor #MA01313.