🔌 Cal Spas® OC Series Replacement Circuit Board — ELE09100330 — Balboa® 55861 — OC850R1A — Duplex Digital — 8-Pin Phone Cable
Genuine OEM replacement circuit board for Cal Spas® OC Series hot tubs — Duplex Digital, 8-pin phone cable, VS family Balboa M7® technology — includes on-board transformer.
⚠️ IMPORTANT — PLEASE READ BEFORE ORDERING
- Chip number verification required. The chip for this board is OC850R1A. Locate the chip sticker on your existing board and confirm it reads OC850R1A before ordering.
- Balboa number check. You can also verify by locating the Balboa 5-digit number on a white sticker on your existing board — it should read 55861. This sticker always starts with a “5” and is located on the board itself.
- Do not order based on appearance. Many Cal Spas circuit boards look nearly identical. Always order based on chip number or Balboa part number, not appearance.
- Board includes an on-board transformer. This board has an integrated transformer — confirm your existing board also has an on-board transformer before ordering.
- DIP switch and voltage configuration required. This board is not plug-and-play. Correct voltage setup, component wire positioning, and DIP switch settings must be applied. Refer to the wiring schematic on the back of the spa pack cover.
📋 Product Overview
The Cal Spas® ELE09100330 is the genuine OEM replacement circuit board for Cal Spas OC Series hot tubs, manufactured by Balboa Water Group (Balboa part number 55861). This is a Duplex Digital board using an 8-pin phone cable topside connector. The board belongs to Balboa’s VS family, using the patented M7® temperature and water flow sensing technology and universal control platform. A distinguishing feature of this board is the integrated on-board transformer.
The board is identified by chip number OC850R1A and Balboa number 55861. It is also known by the alternate Cal Spa part number CALELE09100330.
✨ Key Features
✅ Genuine OEM replacement circuit board — Balboa-manufactured for Cal Spas® OC Series
✅ Cal Spa Part Numbers: ELE09100330 / CALELE09100330
✅ Balboa Part Number: 55861
✅ Chip: OC850R1A
✅ Type: Duplex Digital
✅ Connector: 8-pin phone cable
✅ Platform: VS family — Balboa M7® technology
✅ Includes integrated on-board transformer
✅ For Cal Spas® OC Series hot tubs
✅ Factory-new — never installed
✅ Manufacturer’s warranty included
🔧 Technical Specifications
| Specification | Value |
|---|---|
| Cal Spa Part Number | ELE09100330 |
| Alternate Cal Spa PN | CALELE09100330 |
| Balboa Part Number | 55861 |
| Chip Designation | OC850R1A |
| Board Type | Duplex Digital |
| Connector | 8-pin phone cable |
| Platform | VS family — Balboa M7® |
| Transformer | On-board transformer included |
| System | Cal Spas OC Series |
| Condition | New — genuine OEM |
| Returns | Non-returnable |
| Warranty | Manufacturer’s warranty |
⚠️ For voltage, amperage, heater output, pump configuration, and breaker specifications, refer to the wiring diagram and rating label on the back of your spa pack cover.
🔗 Compatibility Guide
Compatible System:
This board is for Cal Spas® OC Series hot tubs using the OC850 control system. The board is identified by:
- Chip sticker: OC850R1A (on or near the board)
- Balboa 5-digit number: 55861 (on a white sticker, always starting with “5”)
- On-board transformer: present on the existing board
- Topside connector: 8-pin phone cable
How to Confirm Compatibility:
- Locate the chip sticker on your existing circuit board — confirm it reads OC850R1A
- Locate the white Balboa sticker on the board — confirm the 5-digit number reads 55861
- Confirm the existing board has an on-board transformer
- Confirm the topside panel connects via an 8-pin phone cable
⚠️ Contact Parts4Tubs if you cannot locate the chip number or Balboa sticker, or if you are unsure whether this board is the correct fit for your Cal Spa.
Part Number Cross-Reference:
| Part Number | Notes |
|---|---|
| ELE09100330 | Cal Spa PN — this board |
| CALELE09100330 | Alternate Cal Spa PN format |
| 55861 | Balboa PN |
| OC850R1A | Chip designation |
🛠️ Installation Requirements
⚠️ Installation must be performed by a licensed electrician in compliance with NEC and all applicable local codes.
Pre-Installation Checklist:
- [ ] Confirm chip reads OC850R1A on existing board
- [ ] Confirm Balboa sticker on existing board reads 55861
- [ ] Confirm existing board has an on-board transformer
- [ ] Confirm 8-pin phone cable topside connection
- [ ] Obtain wiring schematic from back of spa pack cover before starting
- [ ] Photograph all wiring connections and DIP switch positions before removal
- [ ] Disconnect all power at GFCI breaker or service disconnect
- [ ] Allow capacitors to discharge before handling board
Electrical Requirements:
| Requirement | Specification |
|---|---|
| GFCI | Class A GFCI required — NEC Article 680 |
| Ground & Bonding | Required — NEC Article 680 |
| Dedicated Circuit | Required |
| Disconnect Box | Within line of sight of spa, at least 5 ft away |
| Voltage | Refer to spa pack wiring diagram and rating label |
| Wire Type | Copper conductors only |
⚠️ Safety Warnings
- ⚠️ ALWAYS disconnect all power before circuit board work
- ⚠️ Licensed electrician installation required; NEC Article 680 compliance mandatory
- ⚠️ GFCI required; grounding and bonding required per NEC Article 680
- ⚠️ Do not order based on appearance — confirm OC850R1A chip and Balboa 55861
- ⚠️ Board has on-board transformer — confirm your existing board matches this configuration
- ⚠️ DIP switch and voltage configuration required — refer to wiring schematic on spa pack cover
- ⚠️ Damage from incorrect installation is NOT covered under warranty
❓ Frequently Asked Questions
Q: How do I confirm this is the correct board for my Cal Spa? A: There are two ways to confirm. First, locate the chip sticker on your existing board — it should read OC850R1A. Second, find the white Balboa sticker on the board — the 5-digit number printed on it should read 55861. If both numbers match and the board has an on-board transformer with an 8-pin phone cable connector, the ELE09100330 is your correct replacement. If you cannot locate these identifiers, contact Parts4Tubs with your Cal Spa serial number for assistance.
Q: What does “on-board transformer” mean and why does it matter? A: Some circuit boards have an external transformer housed elsewhere in the control box, while others have the transformer integrated directly onto the circuit board itself. This board (ELE09100330) includes an on-board transformer. This is a critical distinction — if your existing board does not have an on-board transformer, this is not the correct replacement for your system.
Q: What is the VS family / Balboa M7® technology? A: The VS (Value Series) family is a Balboa control platform that uses their patented M7® technology for integrated temperature and water flow sensing. No separate pressure switch is required on VS family boards.
Q: What is “Duplex Digital”? A: Duplex Digital refers to the topside control panel communication type used by this board. It indicates the board is designed to work with Cal Spas’ Duplex Digital topside panel. Confirm your existing topside panel is a Duplex Digital type.
Q: What warranty is included? A: Manufacturer’s warranty (Cal Spas / Balboa). Damage from incorrect installation is not covered.
✅ Why Choose the Cal Spas® ELE09100330 (Balboa® 55861)
✅ Genuine OEM replacement circuit board — Balboa-manufactured for Cal Spas
✅ OC850R1A chip — correct for Cal Spas OC Series systems
✅ Duplex Digital, 8-pin phone cable — direct topside panel match
✅ On-board transformer included — no separate transformer required
✅ VS family Balboa M7® technology — proven platform
✅ Factory-new — never installed
✅ Manufacturer’s warranty included
🤝 Why Buy from Parts4Tubs
✅ Fast US shipping
✅ Chip and Balboa number verification support — contact us before ordering if unsure
✅ Competitive pricing
⚡ Summary
The Cal Spas® ELE09100330 (also CALELE09100330, Balboa® 55861, chip OC850R1A) is the genuine OEM replacement circuit board for Cal Spas OC Series hot tubs. It is a Duplex Digital board with an 8-pin phone cable topside connector, built on Balboa’s VS family M7® platform, and features an integrated on-board transformer. Identify the board by locating the OC850R1A chip sticker or the Balboa 55861 number on a white sticker on your existing board before ordering. Non-returnable; manufacturer’s warranty included.
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 are looking for things like setting the voltage as a lot of PCBs can be configured to run on both 115V and 230V.
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.
You turn on the hot tub and it trips the breaker – it is not common for a new PCB to fail out of the box (I have not seen one yet!) However, a common mistake is that the voltage has not been set correctly. If it is set for 115V and then you try and turn it on, the current draw will be a lot more (twice) than expected and the breaker will trip.
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. As mentioned, if the pack is set to 115V and your pump is meant for 230V, it will draw twice the current at half the voltage and trip your breaker. Check the manual for info on how to set the voltage.



