How to replace a hot tub circuit board

Replace Balboa PCB ImageReplacing a circuit board isn't complex if you follow this simple guide.

This guide is mainly for people that have hot tubs with non Chinese control systems, however the principles are roughly the same, and apply when doing the same.

Note: this guide doesn't show you how to test, repair or upgrade a circuit board, for this you will need to check out our other articles and blogs.

Getting the right board

In most situations it is the detail on the actual printed circuit board that is required, not the make and model of the hot tub or the code on the box, for example on a Balboa circuit board you will have a white sticker that has the model of the board with a 5 number code (see image below) and a basic description, a good example of this is Balboa GS500Z PCB, it has a sticker on the side of the transformer that says S/N 54510-011808060001 (then it has a barcode) Board Balboa GS500Z.

Note all Balboa GS boards have GS500Z written in the bottom left hand corner, however this is a generic board that is then built with various components so therefore changes to a GS501Z or GS510DZ or GS523DZ, again defined by the sticker on the board and not the code on the green part of the board.

Examples of codes on circuit boards.

Replacement Balboa GS500Z Replacement Balboa GS510SZ Not A Replacement GS500Z

The images above show the correct detail on images 1 and 2 but image 3 show the wrong detail, image 3 is actual a GS510DZ even thou its says GS500Z on the green part of the board (note: its a generic circuit board).

Replacing a OEM board for a generic circuit board

OEM means 'original equipment manufacturer', when replacing a OEM board you need to look for the same detail but it usually will have an abreviasion in front of it, for example a Hydropool circuit will say HPL500Z, or an Elite Spa Board May say ES500Z. The GS detail has been left out and although the board may look similar it may have been altered slightly, this is where cross comparing the control panel (keypad) comes into play. If the control panel layout is the same the circuit board will be the same, for example.

Hydropool PanelBlueWhale Spa Panel Image

The above images show panels that identify that the board can be changed for a generic circuit board, if the buttons relate to the board in the correct locations, of course the overlay is just an image so can be any colour or design as long as the buttons are in the correct location.

Note: the experience of a good retailer will always help you to be exact and you just need to provide them with the correct detail to get the right part.

Take a photo

If in doubt send your retailer a picture of the panel and the overlay, the worst is they may ask you for more information. Getting the correct circuit board for a hot tub isn't always easy and a third level of detail may need to acquired, if you have a board that is OEM and the panel looks correct but the jet button does more pumps than replacement generic panel then you will probably have to buy the higher priced OEM board from the manufacturers retailers.

Replacing a board with a different brand.

Simply put, the companies that make the various brands have made it impossible to interchange the boards, the connections and electronics are not compatible with each other.

What if my board has been discontinued

However it is possible to change a complete system if there is no availability, please see other guides and article on hot tub control system upgrades.

Changing a hot tub Circuit Board

Important: first take a few photos of your old board in situation with cables and label the cables if you have a multipull of the same type and colour.

Make a note of jumpers on the old board so you can set them on the new board, however although most hot tub circuit boards don't need programming never presume the settings for the new board are identical, take time and adjust them to match the components and requirement for the power of your spa.

Find the manual for the board online, or ask the supplier of the board to email one to you as a PDF, just in case you need reset it or the connections on the board are in a slightly different place. Worst scenario you may learn something :)

Lastly don't connect the heater or element until you are sure the pumps are working and water is flowing through, so you don't burn it out.

Testing after replacement

Test everything twice.

You will need a multimeter to test the board, make sure its getting the correct voltage, the panel is working correctly, outputs to the components all work and the power to the heater, if you have an AMP clamp maybe even test the amperage at the element.


Remember make sure you are 100% sure its the circuit board that is faulty before you buy a replacement, be confident you have tested everything, and proved that the damage on the old board wasn't caused by anything that can damage the new board that you are about to fit.

Many retailers won't accept a new hot tub circuit board back if its been taken out its packaging or if the item has been fitted, have confidence and if you don't get qualified electrician in to test for you, note we said electrician in rather than hot tub engineer because most hot tub engineers don't have any electrical training or qualifications.

For more detail on replacing a hot tub circuit board please send an email or give us a call via the detail on our contact us page

The following videos duplicate the detail above, but may be useful

Please note all Hot tub Parts sold are UK Spec, which means designed for 230 V at 50Hz