Question: Going through my Magna 3, I noticed that if offers many fault codes. Can you post specific directions on what causes them and how to remedy?

Answer: The Magna 3 series has 15 fault codes with brief descriptions on what is causing them to appear. Most of the answers can be found in the Magna 3 FAQ section on the main menu of this site. By far the two most common fault codes are a “57” which refers to “dry running” and a “88” referring to an internal sensor fault.  

The reason of these two error codes is often caused by small fragments of particulates (debris, magnetite, flux, etc) that is caught in front of the sensor eye thinking its not getting water flow. (The good news is that there is nothing wrong with the sensor, if it was truly defective it would cease to work when installed.)

The short term fix is to pull out the sensor and clean it. Instructions are at

Spirotherm VDT series

The long term fix is to install a Spirotherm air and dirt eliminator (VDT series) which will remove 100% of the entrained air, 100% of the entrapped air and 99.8% of the dissolved air plus remove any particulates down to microns. Note: Do not waste your money on the “magnet” types. The Spirotherm VDT will do everything they will do and much more without having to pull it apart to clean out.

Below is the list of fault codes and their corrective actions. More details and troubleshooting tips can be found under Magna 3 FAQ’s menu.


Once you have corrected the fault code issue, I often go to SETTINGS, drop down the menu to the bottom option which is GENERAL SETTINGS, scroll down to RETURN TO FACTORY SETTINGS. Being that the pump is also a computer, I like to start with a clean slate after having code issues.

If you need support, go to the video section on this site and see how Reece Robinson from Grundfos goes through the settings or call your local wholesaler for assistance.