💡 Balboa GS510SZ PCB – Serial Standard Dual Pump Spa Control Board

Dual pump circuit board for GS501SZ and GS510SZ control boxes – compatible with Serial Standard VL range topside controls.

⚡ Product Overview

BALBOA GS510SZ PCB is designed for use with the GS501SZ and GS510SZ control boxes, supporting pumps, blower, heater, ozone, light, and more. It is compatible with the serial standard VL range such as the VL700S and the VL701S.

This board offers dual pump capability with Pump 1 (single or dual-speed with optional circulation) and Pump 2 (single-speed), making it suitable for hot tubs requiring enhanced jet performance. Commonly used with Spaform and similar brands.

⚠️ Important Information: The reference used now by Balboa is G1552 and replaces previous GS501SZ & GS510SZ Control Boxes and PCBs (54515, 54516, 54650, 54517, 54518).

🌟 Key Features

✅ 230V 50Hz Operation – Designed for UK and European electrical systems

✅ Dual Pump Support – Pump 1 (single/dual-speed + circ) and Pump 2 (single-speed)

✅ J17 Port – Air blower or single-speed pump (10A fuse protection)

✅ Air Blower Output – Yes (optional)

✅ Built-in Heater Control – Integrated heater management

✅ Ozone Ready – Ozone generator output included

✅ 12V Lighting – 12V spa light output

✅ M7 Sensor System – M7 sensors (x2)

✅ No Pressure Switch Required – Simplified installation

✅ Serial Standard VL Panel Compatible – Works with VL700S, VL701S

✅ Replaces Multiple Part Numbers – 54515, 54516, 54650, 54517, 54518, 53642

🔩 Technical Specifications

Specification	Value
Brand	Balboa
Model / Series	GS
Product Type	PCB
Current Reference	G1552
Input Voltage	230V
Frequency	50Hz
Pump 1	Single or dual-speed + circulation pump (if required)
Pump 2	Single-speed
Air Blower	Yes (optional)
J17 Port	Air blower or single-speed pump (10A fuse protection)
Heater Output	Yes
Ozone Output	Yes
Light Output	12V
Sensors	M7 x 2
Pressure Switch	No
Length	280 mm
Width	130 mm

✅ Compatibility Guide

Compatible Control Boxes

Control Box	Compatibility
GS501SZ	✅ Compatible
GS510SZ	✅ Compatible

Replaces Part Numbers

Part Number	Status
54515	✅ Replaced by G1552
54516	✅ Replaced by G1552
54650	✅ Replaced by G1552
54517	✅ Replaced by G1552
54518	✅ Replaced by G1552
53642 (GS510S)	✅ Replaced by G1552

Compatible Topside Panels

Panel	Range	Compatibility
VL700S	Serial Standard VL	✅ Compatible
VL701S	Serial Standard VL	✅ Compatible
Serial Standard VL range	–	✅ Compatible

Compatible Hot Tub Brands

Brand	Compatibility
Spaform	✅ Commonly used

🎛️ Board Functions & Controls

Pump Control

Output	Function	Configuration
Pump 1	Main jet pump	Single or dual-speed
Pump 1 Circ	24hr circulation	Optional (with Pump 1)
Pump 2	Secondary jets	Single-speed

J17 Port Options

Option	Specification
Air Blower	Optional output
Single-Speed Pump	Alternative option
Fuse Protection	10A

Additional Outputs

Function	Specification
Air Blower	Yes (optional)
Heater	Yes
Ozone	Yes
Light	12V

Sensor System

Feature	Specification
Sensor Type	M7
Quantity	2
Pressure Switch	No

🔧 Installation Requirements

⚠️ IMPORTANT: This should be done by an experienced tradesman or a competent individual as a faulty install could result in board damage and invalidate the warranty.

Pre-Installation Checklist

• [ ] Verify this is a GS501SZ or GS510SZ control box
• [ ] Disconnect all power at the isolator/breaker
• [ ] Photograph existing wiring connections
• [ ] Note existing DIP switch settings (if applicable)
• [ ] Allow capacitors to discharge (wait 5 minutes minimum)

Electrical Requirements

Requirement	Specification
Supply Voltage	230V
Frequency	50Hz
J17 Fuse	10A
RCD Protection	Required (30mA recommended)
Earth Connection	Mandatory

💡 Tip: Label or photograph all connections before removing the old board.

⚠️ Safety Warnings

Electrical Safety

• ⚠️ ALWAYS disconnect power before any work
• ⚠️ Installation by experienced tradesman or competent individual required
• ⚠️ Ensure correct voltage supply (230V, 50Hz)
• ⚠️ Verify RCD protection is installed and functioning
• ⚠️ Never operate spa with covers removed from electrical components

Important Notes

• ⚠️ This PCB is for GS501SZ and GS510SZ control boxes only
• ⚠️ Must not be fitted to any other device/product
• ⚠️ Faulty install could result in board damage
• ⚠️ Faulty install will invalidate the warranty

🎯 Ideal Applications

Application	Suitability	Notes
♨️ GS501SZ Systems	✅ Compatible	Direct replacement
♨️ GS510SZ Systems	✅ Compatible	Direct replacement
♨️ Spaform Hot Tubs	✅ Commonly used	GS501SZ/GS510SZ systems

This board is designed for:

• Hot tubs requiring dual pump operation (Pump 1 + Pump 2)
• Replacing faulty GS501SZ or GS510SZ circuit boards
• Systems using Serial Standard VL range topside controls (VL700S, VL701S)
• Spas requiring pump, blower, heater, ozone, and 12V lighting control

❓ Frequently Asked Questions

Q: How do I know if this board fits my spa? A: This board is designed for GS501SZ and GS510SZ control boxes, commonly found in Spaform hot tubs. Check your existing board part number against the compatibility list (54515, 54516, 54650, 54517, 54518, 53642).

Q: What is the current Balboa reference for this board? A: The reference used now by Balboa is G1552, which replaces previous GS501SZ & GS510SZ PCBs (54515, 54516, 54650, 54517, 54518).

Q: What topside panels work with this board? A: Compatible with Serial Standard VL range topside controls including VL700S and VL701S.

Q: What’s the difference between GS510SZ and GS510DZ? A: The GS510SZ (G1552) uses Serial Standard VL panels (VL700S, VL701S). The GS510DZ (G1553) uses Deluxe VL panels (VL801D, VL802D). Both have dual pump support.

Q: Does this board have air blower output? A: Yes, optional air blower output is available via the J17 port (10A fuse protection). The J17 port can also be used for a single-speed pump instead.

Q: What sensors does this board use? A: The board uses M7 sensors (x2) and does not require a pressure switch.

Q: Can I install this myself? A: This should be done by an experienced tradesman or a competent individual. Faulty installation could result in board damage and invalidate the warranty.

Documentation

• Tech Sheet

🏆 Why Choose the Balboa GS510SZ PCB

• ✅ Dual Pump Capability – Pump 1 + Pump 2 for enhanced jet performance
• ✅ Balboa Quality – Trusted brand in spa control systems
• ✅ 230V 50Hz – Designed for UK electrical systems
• ✅ Current Reference G1552 – Latest Balboa replacement for GS501SZ/GS510SZ
• ✅ Flexible J17 Port – Air blower or single-speed pump option
• ✅ M7 Sensor System – No pressure switch required
• ✅ Serial Standard VL Panel Compatible – Works with VL700S, VL701S
• ✅ Multi-Part Replacement – Replaces 54515, 54516, 54650, 54517, 54518, 53642

🤝 Why Buy From Parts4Tubs

• ✅ UK-based company with local support
• ✅ Fast UK delivery
• ✅ Expert technical advice from spa specialists
• ✅ Competitive pricing
• ✅ Full warranty support
• ✅ Easy returns within 30 days
• ✅ Compatible parts and accessories available
• ✅ Help with identifying correct replacement board

✨ Summary

The Balboa GS510SZ PCB (current reference G1552) is a dual pump replacement circuit board for GS501SZ and GS510SZ control boxes. Operating at 230V 50Hz, this board supports Pump 1 (single or dual-speed with optional circulation pump), Pump 2 (single-speed), optional air blower or additional single-speed pump via J17 port (10A fuse protection), heater, ozone, and 12V lighting. Uses M7 sensors (x2) and does not require a pressure switch. Compatible with Serial Standard VL range topside controls including VL700S and VL701S. Commonly used with Spaform hot tubs. Replaces previous part numbers: 54515, 54516, 54650, 54517, 54518, and 53642 (GS510S). Dimensions: 280mm × 130mm. Installation by an experienced tradesman or competent individual is required.

Finding and identifying a replacement Hot Tub Circuit Board (PCB)

If you are looking to replace a failed PCB on your Hot Tub’s spa pack, then quite often identifying the part that you need can be the hardest thing.

Firstly, you are looking for a model number on the actual circuit board itself. Having the model or serial of your hot tub is not going to help at this point, you need to find the number on the PCB itself.

Now, with certain brands of PCB, the number of the replacement PCB that you need is not going to match identically the one you are replacing. Why is that I hear you ask?

Well, normally, it is an updated version. This means that it might have updated firmware on the PCB or be a later revision. Normally, this means that the part number would be slightly different. This is usually indicated with a “12345678 -x” at the end of that part number where x indicated a firmware revision.

In some cases, there will be some following letters on the part number of the circuit board, “12345678 -x MAS” this can indicate that the PCB was used for an OEM meaning it was produced for a certain hot tub manufacturer and the letters identify the manufacturer.

This means if you source an original PCB, it will not have the letters, but will in most cases work just fine.

It can be confusing I know!

What if you can’t find a model number?

If you can’t find a model number on the PCB itself, then you need to look for a model number on the spa pack. Normally, there is a sticker on the outside of the spa pack that tells you the current ratings and input voltages etc and this will have a model number.

In general, most spa packs in the USA are manufactured by Balboa, Hydro-Quip, ACC or Gecko. I know I am generalising here, but if you have a spa pack that has the brand of your hot tub on, it will be an OEM so the key is identifying who made the original box.

From there, you can normally find an original PCB that you will be able to switch out.

For example, the Balboa VS (value series) is a very popular spa pack that has been used by multiple hot tub manufacturers under their own brand names. Whatever they have called it, strip it back and it is still a Balboa VS.

Visual Inspection

One of the most important things you can do when you are looking for a replacement is to visually inspect the PCB that you have versus the picture online of the replacement you are considering. They need to look the same even if there are the differences in firmware revisions or OEM part numbers, you should be visually replacing a PCB that looks like the one you have.

Configuring a replacement Hot Tub Circuit Board (PCB)

When you get a new PCB, you are more than likely going to need to configure it. Most PCBs have a number of different modes and setups that the can operate in. For this, you will need to manual or spec sheet to guide you.

For things like DIP switches, most of the time you can copy the settings from your original circuit board.

You may need to move jumpers or even wires to configure voltages – the key here is that you read the schematic and don’t expect the PCB to just work out of the box – it usually doesn’t.

Troubleshooting a Hot Tub Circuit Board (PCB)

Here are some common things you will see when you replace a PCB on a hot tub.

You press the buttons on the topside control and they don’t control the right parts (pumps or blower etc) – this is a mode configuration thing and you will either need to change some DIP switches on the PCB or an internal or low level programming mode on the topside control. Check the manual for how to do this.

To check this, unplug all of your kit – heater, pumps, blower and then turn on the PCB. If it trips with nothing plugged in, usually the voltage is incorrectly set and what is happening is that live current is being sent to the ground – because you have 4 wires into the PCB rather than 3. Current on the ground loop causes the trip. Check the settings to make sure it is configures for 230V.

It might not trip until you physically turn on a pump or a blower.