How to Read a Spa Pack Wiring Diagram (Setup Numbers, DIP Switches and Pin-Outs)

Last updated: September 2026

Have you ever taken the lid off a spa pack, looked at the wiring diagram inside and felt completely lost? You’re not alone. It’s a page of tiny print, tables and symbols, and it isn’t written for beginners. But once you know what each part of it is for, it answers almost every question you’ll have about setting up your pack.

In this guide I’ll walk through a spa pack wiring diagram section by section, building on my video “Spa pack wiring diagrams explained”. I’ll mostly use Balboa packs as the example, because that’s what most DIY builders use, with notes on ACC for US builds.

What the spa pack does

The spa pack is the control centre of your hot tub. The mains supply goes into the pack, and the pack switches power out to the heater, the jet pumps, the circulation pump, the blower, the ozone generator and the light. In its most basic form it’s a set of relays controlled by a circuit board. You don’t wire the pumps to their own supplies.

The wiring diagram is the map of all of that: where the power comes in, where each piece of equipment plugs in, and how the pack decides what to run. If you want the whole electrical picture, from the consumer unit or panel to the pumps, read Hot tub wiring explained alongside this.

Safety first

Before you open a spa pack, turn the power off at the breaker and the local isolator, and make sure it can’t be switched back on while you work. You can read a diagram and plug in pumps and a topside with the power isolated. The supply itself, from the consumer unit or panel to the pack’s terminal block, should be installed by a qualified electrician. In England and Wales it’s notifiable under Part P, and in the USA it usually needs a permit and inspection. A guide to hot tub electrics explains who does what.

Where to find the wiring diagram

• Inside the lid. On Balboa packs, a circuit diagram is printed on the underside of the cover.
• The tech sheet. Balboa publishes a tech sheet for each system on its system tech sheets page. It has the same information, easier to read, plus the software version and board part numbers.
• The manual. Packs like the ACC SmartTouch come with installation guidelines that cover the wiring.

Not sure which Balboa board you have? See How to identify a Balboa circuit board.

The parts of a wiring diagram

Section	What it tells you	Who uses it
Supply terminal block	Where line, neutral and earth (UK) or L1, L2, neutral and ground (USA) connect, and the rated current	Your electrician
Setup (configuration) table	Which setup number matches your pumps, blower and circ pump	You
DIP switch table	Test mode, load limits, memory reset and heater cool-down	You, matched to the circuit your electrician installed
Output sockets and pin-outs	Which socket each pump and accessory plugs into, its voltage and amp limit, and which pin is high, low, common and earth	You
Jumpers	Voltage settings, such as the heater voltage on US dual-voltage packs	You or your electrician
Fuses	Which fuse protects which circuit, and its rating	Anyone troubleshooting

1. The supply terminal block

This shows where the incoming supply connects. On a UK Balboa pack on a single-phase supply, it takes line, neutral and earth. Balboa’s BP packs are typically set up for 16A or 32A service, with a 20A or 40A maximum breaker. On a US 240V pack, you’ll usually have L1, L2, neutral and ground. The neutral is there for the 120V parts inside the pack, such as an ozonator. Some US packs, like the Balboa BP7, also allow a 3-wire supply without a neutral. The diagram shows which your pack needs.

Your electrician sizes the circuit, cable and protection from the pack’s rating, the run length and how the cable is installed. For a UK tub that means a dedicated circuit with at least a 30mA Type A RCD, and in the USA, GFCI protection.

2. Jumpers and voltage settings

Some packs, mostly US ones, can be set for different supplies. Balboa uses a jumper for the heater voltage: the BP6013G1 tech sheet, for example, shows jumper J24 on the centre two pins for 240V, and two jumpers for 120V. On the ACC SmartTouch 1000, you move wires on the terminal block to go from 120V to 240V. Pumps and accessories on a dual-voltage pack also need to be the right voltage for their outputs.

Get this wrong and a 240V heater on a 120V setting gives only a quarter of its power, or pumps struggle and overheat. Check it against the diagram before anything else. For a DIY block or concrete tub, you want 240V anyway.

3. The setup (configuration) table

One pack can run lots of different combinations of equipment, so you have to tell it what you’ve plugged in. The setup table lists each setup number and the equipment it expects. Here’s the important bit: the same equipment has a different number on different packs.

Equipment	Balboa BP8 (18 setups)	Balboa BP601 (6 setups)
Circulation pump + 1-speed jet pump + 1-speed blower	13	4
2-speed jet pump + 1-speed blower, no circulation pump	17	3

Always use the table in your own lid. The setup also changes what a socket does. The same output might run a blower in one setup and a second pump in another, so read the socket assignments for the setup you’ve chosen. A common mistake is forgetting a dedicated circulation pump when you pick your setup. If the pack thinks there’s a circ pump that isn’t there, it tries to filter with it and never does.

How you enter the setup depends on the topside. On the older Balboa TP-series topsides it’s DIP switch 1 on, power up, then Warm, Warm, Light, Warm, scroll with Warm, and save with Light. Newer menu-driven topsides use a test menu. I’ve covered both in How to configure a Balboa spa pack and Program the Balboa BP8 using a TP700.

4. The DIP switches

These tiny switches on the circuit board change specific settings. On the Balboa BP packs I’ve used:

• A1: test mode (normally off; on while you enter the setup).
• A2, A3, A4: how many high-speed devices (pumps or blower) can run with the heater. They add together, and all off means no heat while any high-speed pump or blower runs.
• A5: special amperage rule.
• A6: memory reset.
• A7: heater cool-down time.

Functions vary between packs. On the BP601, for example, A4 sets the heater cool-down instead. So always check your own lid. Set the load switches to match the circuit your electrician installed, not “everything on”. The breaker is there to protect the cable, not to be your load control. On a 16A UK supply, that means letting the pack switch the heater off while the jets run.

5. Output sockets and pin-outs

The diagram shows each output socket, what it’s for, its voltage and its maximum current. Check each one against what you’re plugging in. Just because an output says 12V doesn’t mean you can plug any 12V light into it. I learnt that the hard way with a pool light and three blown boards.

Most packs use multi-pin plugs such as the white AMP-style connectors. The housings are keyed so they only go in one way, and the diagram shows which pin position is high speed, low speed, common and earth. When you make up or check a pump cord:

• Hold the plug the same way round as the drawing (the flats and corners on the housing help) before you count pins.
• Follow the pin-out, not the wire colours. Colours vary between countries and manufacturers.
• Remember that brands differ. Balboa and ACC order their pins differently, so a cord made up for one isn’t right for the other.
• A single-speed pump uses a 3-core cable, and a two-speed pump a 4-core cable. Get high and low swapped and the pump runs on the wrong speed.

There are pin-out drawings for both brands in Hot tub wiring explained, and the blower specifically in How to wire a hot tub blower.

6. Fuses

The fuse list tells you which fuse protects which circuit, and its rating. Even if electrics isn’t your thing, it’s worth knowing where it is. If a fuse blows again straight after you replace it, something else is wrong, so don’t keep fitting bigger ones.

Reading a diagram: a worked example

Say you’re building a tub with a circulation pump, one single-speed jet pump and a blower, on a Balboa pack with the 18-setup table:

1. Find the setup table in the lid. Your equipment matches setup 13.
2. Check which socket the table assigns to the circ pump, jet pump and blower in setup 13, and plug each one into its socket.
3. Check each device’s current against the output’s rating.
4. Set the DIP switches for your supply. On a smaller circuit, that means limiting what runs with the heater.
5. Enter setup 13 on the topside, then turn off test mode.
6. Power up and test each button: jets, blower, light and heat.

Common mistakes

• Using another pack’s setup number because “it worked on my mate’s tub”.
• Wiring pumps by colour instead of by the pin-out.
• Leaving a US dual-voltage pack on the wrong voltage setting.
• Setting the DIP switches for more current than the supply can take.
• Plugging something into an output it wasn’t rated for.
• Blaming the wiring when the setup number is wrong.

Troubleshooting after wiring

• A button turns on the wrong thing: check the setup number, then which socket each device is in.
• A pump runs on the wrong speed: high and low are swapped at the plug or at the pump.
• The heater goes off when the jets run: usually the DIP switch load limit doing its job.
• A flow error: it’s probably not the wiring. See Hot tub FLO error, or for ACC packs, PSOL and PSOH errors.
• The breaker or RCD trips: see Hot tub tripping the breaker?

Planning your own build?

Wiring diagrams are far less scary when you’ve chosen your pack, pumps and blower together and planned where everything goes. The Ultimate Hot Tub Control Room Guide shows how to lay out the pack, pumps and wiring, and my DIY hot tub plans include a full parts list. Spa packs, pumps and cords are available from parts4tubs.co.uk in the UK and parts4tubs.com in the USA.

FAQs

Where is the wiring diagram on a spa pack?

On Balboa packs it’s printed inside the lid. The same information is in the tech sheet for your system on Balboa’s website, and other brands include it in the installation manual.

What does the setup number on a spa pack do?

It tells the pack which equipment is connected: how many pumps, whether they’re single or two-speed, and whether there’s a blower or circulation pump. The numbers differ between packs, so use the table in your own lid.

What do the DIP switches on a Balboa spa pack do?

Switch 1 is test mode. On many Balboa packs, others set how many high-speed pumps can run with the heater, plus memory reset and heater cool-down. Check your lid, because functions vary.

Can I wire a pump by matching the wire colours?

No. Colours vary between manufacturers and countries. Follow the pin-out in the diagram, and check the pump’s own terminal diagram.

Can I wire the supply to my spa pack myself?

The supply should be installed and connected by a qualified electrician. In England and Wales it’s notifiable under Part P, and in the USA it usually needs a permit and inspection.

Got a diagram you can’t make sense of? Post your pack model in the comments below. I read them all.

Cheers,
Andi

You can also find me on my socials;

Can I Help You?

If I can help you in any way I would love to hear from you. You can get in touch using the form below.

Thanks - Andi

 

Hi, Andi here. I own Buildahottub.com and also write all of the articles and info pages on the site. Some years back now, I built my own hot tub but struggled to find the information I needed. So, once my tub was complete, I started this website to help others in their own pursuit of hot tub and plunge pools DIY building information.

Fast forward to 2025, I've helped over 1400+ DIY customers just like you all over the world build hot tubs and pools. Have a good look around the site, there are lots of resources here. Please do get in touch if I can help you. - Cheers, Andi