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Grundfos Hot Water Recirculating Pump Troubleshooting

Bought a Grundfos hot water recirculating pump but it’s already showing signs that something may be off. You probably don’t understand what might go wrong. Before calling a plumber, try fixing it by yourself. 

How do you do Grundfos hot water recirculating pump troubleshooting? 

Grundfos hot water recirculating pump might have a clogged valve or a leaky pipe. Or it might continuously start and stop. You can fix these by checking the valve, pipes, pressure tank, etc. And then take necessary action accordingly. 

Don’t worry, these are the problems people face every day. We provided a step-by-step troubleshooting guide for you. 

Let’s get started-

Grundfos Hot Water Recirculating Pump Troubleshooting: Step-by-Step Instructions 

Grundfos is one of the biggest household hot water recirculating pump manufacturers. The pump works best when the depth is less than 26 feet.0

A control panel on top of the device controls the pump. The pump begins automatically when water is needed. And the machine is powered by a built-in pressure tank. Look for broken or leaky suction pipes as part of your troubleshooting. 

Step 1: Check the Pump 

If the pump does not start, inspect the water supply suction line for damage or blockages. If the unit won’t start due to overheating, provide a supply of cool water via the pump. 

Check for blown fuses. Don’t forget the tripped breakers in the electrical box. Ensure that the discharge pipes and pumps highest points do not exceed 50 feet. 

If it’s in an alarm mode, reset the unit. By pushing the “On/Off” button once, the unit will be reset. To start the pump, press the button once more.

Step 2: Check the Pipe and Valve

If the pump does not stop functioning, inspect the piping for leaks or damage. If you have such problems, you’ll need to fix them. It’s important to detect the problem first.

Check for Pipe Leakage

Here are some common signs to understand if there’s a leakage in your pipe. Do you acknowledge any of these signs? 

Your water bill is surprisingly increasing. Or, the water meter shows that you have water. There’s also a chance of mold forming in your wall. Another sign is your ceiling, wall, or floor might be damaged. 

As needed, make repairs to the piping. Check for clogs in the non-return valve. Sometimes because of the clogs, the valve gets stuck. Clean the valve if you think it needs to be cleaned. 

Unclog the Drain Valve 

You should begin by closing the drain valve and detaching the hose from the drain valve. Then to catch the water, place a couple of towels or a pan beneath the drain valve. After that enter a stiff wire or a wire coat hanger through the drain valve hole.

Make a circular motion with the wire. This will aid in the loosening of the debris. If you were able to clear the drain valve, water should begin to flow through it.

If not, continue inserting the wire until water flows. After that, close the valve and connect the hose. Throughout the process of draining the tank, it’s not unusual for the drain valve to clog.

Repeat this process till the tank is empty.

Step 3: Check Pressure Tank

If the pump begins and stops often, make sure the pressure tank has enough pressure. The pressure in your well tank should be 2 psi lower than the pressure switch’s cut-on point. 

This varies based on the pressure settings in your tank. The majority of well tanks are placed at 30/50. The well pump’s cut-on pressure is 30 psi. The tank’s pressure should be at least 28 psi. Your pressure setting should be 38 psi if your well tank is on a 40/60 pressure switch. 

To check the pressure of the tank, first cut off the power to your well tank. Then drain the well tank outside your home. You can connect a hose in order to do that. After that, locate a pressure gauge and read the pressure. 

In case you’re looking for a good hose, here are our top wicked one’s-

Lastly, adjust the pressure with an air compressor if necessary. 

Step 4: Fix Ground Connection

The pump might produce electric shocks. The ground connection must be properly connected to the pump according to local requirements.

Step 5: Check for Frost Damage

In the winter, there can be frost damage to the pump due to snowfall. If there is a possibility of frost damage, empty the pump through the drain hole. Then remove the union screw on the discharge line. 

Before starting the pump again, make sure it’s filled with liquid.

Step 6: Check to Install a New Valve

If the pump activates whereas no water is being used, clean or replace the internal non-return valve. If you can’t install the valve, call a professional to do so.

So, this is how you troubleshoot Grundfos hot water recirculating pump. If you want to work on your main valve, make sure to cut off the water first. The replacement of the main valve’s cost includes the payment of a plumber. Also, you need to take in the bill of the valve.


Question: Is recirculating hot water worth it?
Answer: Yes, because it saves water by heating the water instantly within 10 seconds. It saves energy and water cost. So, it’s worth it.

Question: How long do the Grundfos pumps last?
Answer: If you maintain it properly, it’ll last over 10 years. In some people’s cases, it lasted up to 20 years too.  

Question: How does a Grundfos recirculation pump work?
Answer: The Grundfos Comfort System comes with everything required to install a hot water recirculation system at home. It doesn’t necessarily have a dedicated return line. The system employs a bypass valve and pump with a 24-hour programmed timer. It maintains hot water accessible in the pipes for instant usage. It was installed in less than two hours.


That’s our complete guide for Grundfos hot water recirculating pump troubleshooting.

People face so many problems with hot water recirculation systems. Because it’s still new to some extent to households. 

With this troubleshooting guide, we hope you will be able to fix your problems. Take care!