Adding Water to Geothermal Loop: 5 Step Guide

We may get commissions for purchases made through links in this post.

A geothermal loop with low pressure can give you a hard time and ruin an entire summer. Well, if you want to save your summer (and winter!), you need to add water to the loop in order to keep the pressure constant.

So what to do when you’re adding water to geothermal loop?

First, attach a garden hose and a repressurization tool with a faucet and run water through them. Then, insert the tool into the PT plug and loosen the burping screw to allow water flow. Lastly, tighten the screw and repressurize the pump to a standard level.

But there’s a catch!

These are only the nuts and bolts of the steps of the whole thing. If you’ve a minute to spare, read along for an insight of all the steps.

So, let’s get to work!

Some Basics Before Getting to The Steps

Geothermal loops can be a bit tricky to work on. So before jumping to the instructions, let’s know some basics about the kind of geothermal system you’re dealing with.

What Is A Geothermal System?

If you’re not familiar with a geothermal loop, it’s a heating and cooling system. And unlike any conventional home comfort system, the geothermal one uses ground sources to loop the heating and cooling process.

How does it work?

The function of a geothermal system is quite simple! In winter, it extracts heat from the ground and carries it to the home to keep it warm.

Simply put, it makes your home cozy! 

However, the function reverses in summer. It collects the heat from your home and passes it to the ground so that you can have a cool relaxing evening after you come home from work.

The geothermal system is also big on efficiency and saving. It saves approximately 70% energy of heating, cooling, and hot water for the homeowners. Really, who wouldn’t want a geothermal system?

5 Steps of Adding Water to A Geothermal Loop

When the pressure in the geothermal system decreases over time, the indoor air quality also reduces. But if you know how to add water to geothermal loop, you’ve got nothing to worry about!

To fix the low water pressure level, you’ll need to follow these steps to fix your geothermal loop.


There are many other  geothermal tools out on the market to assist with your troubleshooting. Here’s a list of products, we think will help you choose a suitable one.

Geothermal Tools

Socket Fusion Commercial Tool Kit - TK-315

Socket Fusion Tool Kit TK-310

Step 1: Locate A Faucet

The first step for you would be to locate a faucet inside or outside your house. Any faucet except the one on the bottom of the hot water heater would do. After that, connect the garden hose to the faucet. Once everything’s set, turn the faucet on and let the water run at full pressure for several minutes. The running water will ensure no air remains in your pipe.

Step 2: Attach The Hose with The Tool

After you run the water through the garden hose, attach it to the repressurization tool. You need to allow more water to run through both the hose and the repressurization tool. In this step, keep an eye on the ductwork as well. Checking all the ductworks is just as important as the ductworks of an electric heater.

Step 3: Insert The Tool Into The Plug

In the third step, you need to insert the repressurization tool into the PT plug of the geothermal pump. And then, add water pressure to the ground loop (If you’re confused about these parts, reading the manual might help you). It’s recommended that the pressure should be around 40 to 70 PSI.

Step 4: Remove The Air And Debris

You can proceed to step 4 once the appropriate pressure level is achieved! Allow the water pressure to remove any air or debris left inside the pump. You need to be extra careful about the pump and remove the debris whenever possible. Not cleaning the debris is dangerous. Turns out, this also causes a pellet stove to blow smoke inside the house

For removing air and debris, you need to loosen up the burping screw, at the end of the pump shaft. This will help the loop pumps to burp . You might ask, why? Well, loosening the screw will stop the air spitting and allow the water to run smoothly. 

After the water flow becomes steady, tighten the screw again and repressurize the loop back to the standard level that is, around 40 to 70 PSI. But, your job is not done yet!

Step 5: Return The Zone Control

After repressurizing the loop, finish the process off by returning the zone control to the system’s previous operating conditions. In case you didn’t know, zone control valves operate the flow to the heat pump of the geothermal loop. Each zone valve has individual flow to a circuit. 

Contingency Plan

The mentioned steps will help you keep the ideal water pressure of your geothermal loop. But after adding water, you must check the pressure level every once in a while. If your geothermal loop is losing pressure again, there might be a possible leak. 

In that case, try to detect and seal the leak. Consult a trained technician if necessary.

Remember: At some point, you might want to install a swimming pool in your backyard. You need to be extra cautious with the geothermal loop when leveling the ground for a swimming pool.


Question: How do you maintain a geothermal system?
Answer: Geothermal systems work efficiently in both seasons. To ensure the good health of your geothermal system, keep it clean, check the consideration pan, clean the drain with a dilute bleaching solution, detect and seal any leaks. If you want, you can make servicing once a year mandatory.

Question: How do you pressure test a geothermal pipe?
Answer: Pressure testing helps you to learn if your geothermal system is doing okay or not. You need to apply pressure up to 12o PSI and wait for an hour. Drop the pressure suddenly to 60 PSI and observe it for the next hour. If the pressure is lower than 60 PSI, adding water to closed loop geothermal will fix the problem.

Question: How often should I service a geothermal system?
Answer: Once a year! If you want to save 70% of energy and enjoy the other benefits of the geothermal system then you should do a yearly check-up with a trained technician. This will increase the lifespan of the system.

Parting Words

Now that you’re done adding water to geothermal loop, you can go back to enjoying your cozy home with your family. So if you want a peaceful living, maintaining a geothermal loop is a must!

Let us know if you were able to add water to geothermal loop by leaving a comment below!

Have a great day!

Richard Allen