💡 Watkins / Hot Spring IQ2020 Heater Relay Board – Orca 50/60 (P/N 77118)

Genuine Watkins Wellness OEM heater relay board for the IQ2020 Orca / Invensys control box — the direct factory replacement for the now-obsolete 76071.

📋 Product Overview

The Watkins IQ2020 Heater Relay Board (P/N 77118) is a genuine OEM replacement heater relay sub-board for the Hot Spring, Tiger River, and Limelight spas using the IQ2020 Orca / Invensys control box system. This board’s specific job inside your IQ2020 control box is to switch power to the spa’s heater through its two onboard relays — when the motherboard signals for heat, the 77118 relays close and pass line voltage to the heater element.

The 77118 is the current factory replacement for the obsolete earlier-generation heater relay board, P/N 76071. It is also sold under alternate reference numbers 3-60-0008 and 1310801-2. It covers model years 2009.5 to 2012.5 specifically — the Orca/Invensys-era IQ2020 control boxes.

⚠️ Important — this is a heater relay sub-board, not a standalone spa controller. The 77118 mounts inside an existing IQ2020 control box alongside the motherboard. You must already have a functioning IQ2020 Orca/Invensys control system installed for this board to be useful. If your heater is dead, the red “HTR ON” LED inside the control box is lit, and/or the existing heater board shows burn/char marks on its front or backside, this is the replacement part.

⚠️ If your spa predates 2009.5, you need the different 77119 heater relay board (for the 2001–2009.5 control box) — not this 77118.

⭐ Key Features

• ✅ Genuine Watkins Wellness OEM heater relay board – factory part manufactured for the IQ2020 Orca 50/60 control system
• ✅ Two onboard relays – switch line voltage to the spa heater under motherboard command
• ✅ Direct replacement for obsolete P/N 76071 – drop-in factory supersession
• ✅ Also sold under alternate P/Ns 3-60-0008 and 1310801-2 – several distributors and documentation references
• ✅ Orca / Invensys circuitry compatible – specifically designed for the 2009.5–2012.5 IQ2020 Orca control box
• ✅ 50 Hz / 60 Hz compatible – per “Orca 50/60” product designation, works in all countries
• ✅ Compatible with Hot Spring, Tiger River, and Limelight spa lines – the three main Watkins Wellness brands using the IQ2020 Orca platform
• ✅ Typical failure diagnosis built in – if the red HTR ON LED is lit but the heater has no voltage across both hot leads, or if the existing board is charred, this is the replacement
• ✅ Genuine Hot Spring / Watkins Wellness factory OEM – not a third-party aftermarket board
• ✅ Non-returnable – spa electrical items are final-sale once opened

🔧 Technical Specifications

Specification	Value
Manufacturer Part Number	77118
Manufacturer	Watkins Wellness (Hot Spring / Tiger River / Limelight)
Product Type	Heater Relay Board (sub-board within IQ2020 control box)
Platform	IQ2020 Orca / Invensys Control Box System
Supersedes	76071 (now obsolete)
Alternate Part Numbers	3-60-0008
Reference Number	1310801-2
Relays	2 heater relays
Frequency	50 Hz / 60 Hz (per “Orca 50/60” designation — works in all countries)
Compatible Model Years	2009.5 to 2012.5 (Orca / Invensys control box era)
Parent Control Box	IQ2020 Orca (Invensys circuitry)
Warranty	Per manufacturer (see Watkins Wellness warranty terms via authorized dealers)
Returnable	⚠️ No — spa electrical items are non-returnable

ℹ️ No standalone electrical ratings: Because the 77118 is a sub-board inside the IQ2020 control box and is controlled by the motherboard, it does not have an independent input voltage, breaker rating, or GFCI specification of its own. All supply-side electrical specs are inherited from the spa’s main electrical installation (typically 240 VAC, Class A GFCI required per NEC Article 680 for all Hot Spring / Watkins Wellness installations).

✅ Compatibility Guide

Spa Lines and Model Year Range

The 77118 heater relay board is specifically designed for the 2009.5 to 2012.5 era IQ2020 Orca / Invensys control box, which was used across Watkins Wellness’s main spa lines during that window:

Spa Brand / Line	Compatibility	Model Year Range
Hot Spring (Highlife Collection)	✅ Compatible	2009.5 – 2012.5 with Orca / Invensys IQ2020
Tiger River	✅ Compatible	2009.5 – 2012.5 with Orca / Invensys IQ2020
Limelight	✅ Compatible	2009.5 – 2012.5 with Orca / Invensys IQ2020

Critical Before-You-Order Check

Before ordering, confirm both of the following:

1. Your spa’s model year falls within 2009.5 – 2012.5
2. Your existing IQ2020 control box uses the Orca / Invensys circuitry

If your control box predates the Orca/Invensys design (i.e., the earlier 2001–2009.5 IQ2020), you need the 77119 heater relay board — NOT this 77118.

Watkins Wellness IQ2020 Product Family — Side-by-Side

Part Number	Product	Model Year Range	Control Box Type
76071	Previous-generation heater relay board (OBSOLETE)	2009.5 – 2012.5 Orca	Superseded by this 77118
77118	Heater Relay Board — Orca 50/60 (THIS PRODUCT)	2009.5 – 2012.5	Orca / Invensys
77119	Heater Relay Board (upgraded design)	2001 – 2009.5	Earlier IQ2020 (pre-Orca)
73223	IQ2020 Control Box (OBSOLETE)	2001 – 2009.5	Invensys main unit
77087 / 77271	IQ2020 Replacement Control Box	Retrofit upgrade	Complete control box replacement
76836	IQ2020 Eagle Control Box	2012.5 – Current	Newer Eagle-generation control box

NOT Compatible With

System	Reason
Pre-2009.5 Hot Spring / Tiger River / Limelight spas	Use the 77119 heater relay board instead
2012.5-and-later Hot Spring spas with IQ2020 Eagle control box (76836)	Different platform generation — Eagle-era parts needed
Balboa, HydroQuip, Gecko, Waterway, or Spa Builders control systems	Different manufacturer entirely
Hot Spot or Freeflow series (if using non-IQ2020 systems)	Some use different control platforms
Caldera Spas models not using the IQ2020 Orca control box	Caldera models use platform-specific boards

Sister Parts Often Replaced Together

Part Number	Description
77087 / 77271	Complete IQ2020 control box (if full control box replacement is needed)
79005 / 79006	New-style IQ2020 temperature sensor thermistors (replace in pairs)
39525 / 39530	Older-style thermistor kit (for earlier IQ2020 control boxes with thermistor ports)

⚙️ Board Functions & Controls

What the 77118 Does

The 77118 is a single-purpose sub-board that sits inside the IQ2020 control box and handles one critical function: switching power to the spa heater under the control of the IQ2020 motherboard.

Component	Function
Relay #1	Heater switching (one of two relays in series for safety)
Relay #2	Heater switching (redundant / paired for safety)
HTR ON LED indicator	The red LED on the motherboard lights when the motherboard commands heat — if this LED is lit but the heater has no voltage, the 77118 is likely the failed component

How It Works in the IQ2020 System

1. The IQ2020 motherboard reads the temperature thermistors (79005 / 79006)
2. When heat is needed, the motherboard lights the red HTR ON LED and sends a low-voltage command signal to the 77118 heater relay board
3. The 77118’s two relays close, switching line voltage through to the spa’s heater element
4. When temperature is reached, the motherboard removes the command signal; the relays open; the heater stops

If the motherboard’s HTR ON LED is lit but no voltage is reaching the heater across both hot leads, the fault is almost always in the 77118 (or its predecessor 76071) — that is the primary diagnostic pattern for needing this part.

🔌 Installation Requirements

⚠️ Installation of spa electrical components must be performed by a licensed electrician or qualified Hot Spring service technician in compliance with the National Electrical Code (NEC), NEC Article 680 (Spas and Hot Tubs), and all local codes. Watkins Wellness’s own owner’s manuals explicitly state: “Refer all servicing to qualified service personnel.”

Pre-Installation Checklist

• [ ] Confirm your spa’s model year is 2009.5 – 2012.5
• [ ] Confirm your IQ2020 control box is the Orca / Invensys variant (not the earlier 2001–2009.5 version)
• [ ] Verify the failure symptoms match typical 77118 failure (HTR ON LED lit + no heater voltage, or visible charring on the existing heater board)
• [ ] Disconnect all power at the house breaker AND the spa disconnect box
• [ ] Allow residual power to dissipate — wait at least 5 minutes after power-off
• [ ] Photograph all wire connections on the existing heater relay board before removal

Electrical Requirements (Spa-Pack Level)

Requirement	Specification
Supply Voltage	Per your spa’s original electrical installation (typically 240 VAC in North America)
Frequency	60 Hz (North America) — the 77118 also supports 50 Hz for export markets
Class A GFCI	Required (NEC Article 680)
Dedicated Circuit	Required
Disconnect Box	Required within line of sight of the spa (NEC)
Grounding	Equipment grounding + bonding (NEC Article 680)

Typical Installation Sequence

1. Power OFF at house breaker AND spa disconnect box — both must be confirmed off with a meter
2. Open the IQ2020 control box to expose the existing heater relay board
3. Photograph the exact wire positions on the existing 76071 or failed 77118
4. Disconnect heater power leads (both hot leads and neutral) from the existing board
5. Remove any ground lug connection from the existing board
6. Remove screws securing the existing board to the control box enclosure
7. Carefully disconnect the low-voltage command connector that ties the board to the motherboard
8. Install the new 77118 using the reverse sequence
9. Transfer the heater’s black, white, and ground wires to the matching terminals on the new 77118 — verify exact placement by referring to the photo taken before removal
10. Reconnect the low-voltage command connector
11. Close the control box cover completely before restoring power
12. Restore power at the disconnect, then the house breaker
13. Allow the spa to cycle through its startup — verify the heater energizes when the motherboard commands heat (HTR ON LED lit AND voltage reaching the heater across both hot leads)

💡 Tip (from installation notes in multiple service references): In older IQ2020 control boxes, the metal guard covering the heater relay board may not seat properly over the new board because of a physical chip location difference. If the metal guard doesn’t fit correctly, it may need to be trimmed. Refer to the Watkins installation instructions PDF if available from your authorized dealer.

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⚠️ Safety Warnings

Electrical Safety

• ⚠️ ALWAYS disconnect power at the house breaker AND spa disconnect box before opening the IQ2020 control box
• ⚠️ Hot Spring / Watkins Wellness owner manuals specify: “Refer all servicing to qualified service personnel”
• ⚠️ High voltage levels exist inside the IQ2020 control box — direct contact can cause severe injury or electrocution
• ⚠️ Verify Class A GFCI protection is installed and operating per NEC Article 680 before returning the spa to service
• ⚠️ Test and reset the GFCI on a regular basis (per Watkins’s owner manual)
• ⚠️ Installation must be performed by a licensed electrician with all grounding connections properly installed
• ⚠️ Never operate the spa with the IQ2020 control box open or its covers removed

Diagnostic Safety

• ⚠️ DO NOT measure voltage from one hot lead to ground and “add” the result — the proper test is to measure across BOTH hot leads to the heater
• ⚠️ The red HTR ON LED being lit does NOT mean the heater is receiving power; it only means the motherboard is commanding heat
• ⚠️ If the existing board shows charring, treat the entire area as a potential fire hazard and inspect all nearby wiring and insulation before installing the replacement

Water & Electrical Safety

• ⚠️ Do not hose down, flood, or allow water to enter the IQ2020 control box
• ⚠️ Inspect the control box seal and gasket before closing up
• ⚠️ Never touch electrical components with wet hands
• ⚠️ Keep all electrical appliances (light, phone, radio, TV) at least 5 ft (1.5 m) from the spa per Watkins’s owner manual

Post-Installation

• ⚠️ Confirm the heater energizes (voltage across both hot leads at the heater) when the HTR ON LED is lit
• ⚠️ Monitor the new board during the first filter cycle for any signs of overheating or burn marks
• ⚠️ Test GFCI operation before returning the spa to regular use

🔍 Diagnostic Symptoms & Troubleshooting

Is the 77118 the Part You Need?

The 77118 is the correct replacement if both of these symptom patterns match:

Symptom Pattern 1: No heat, HTR ON LED lit

• The spa stops heating
• Inside the IQ2020 control box, the red HTR ON LED is lit (indicating the motherboard is commanding heat)
• BUT no voltage is present across both hot leads to the heater element

Symptom Pattern 2: Visible damage to the existing board

• The existing heater relay board shows burn marks on the front side, backside, or both
• Relays on the board appear pitted, melted, or discolored
• Visible scorching around the terminal block

Troubleshooting Table

Symptom	Likely Cause	Action
Spa heats fine but occasionally trips GFCI	Not typically a heater board issue — inspect GFCI, heater element, and main wiring first	Test GFCI; check heater element for failure
Heater never energizes, HTR ON LED NOT lit	Motherboard or thermistor issue, not the 77118	Check temperature thermistors (79005 / 79006) and motherboard
Heater never energizes, HTR ON LED IS lit	Heater relay board (77118) has failed	Replace with 77118
Visible scorching on existing heater board	Relay contact failure / overheat	Replace with 77118; inspect surrounding wiring for heat damage
Heater energizes but spa won’t reach set temperature	Typically heater element degradation, flow issue, or sensor issue — not the 77118	Check heater element resistance, filter cleanliness, and thermistor function
Breaker trips when heat is called	Short in heater element OR failed relay stuck closed	Test heater element first; if good, suspect the heater board

🎯 Ideal Applications

Application	Suitability	Notes
Replacing a failed 77118 in a 2009.5–2012.5 Hot Spring, Tiger River, or Limelight spa	✅ Direct drop-in replacement	Primary application
Replacing the obsolete 76071 predecessor board	✅ Direct factory supersession	77118 is the current-production replacement
Heater-won’t-turn-on service call on Orca/Invensys-era IQ2020 spas	✅ Primary diagnostic match	When HTR ON LED lit + no heater voltage
Spas with visible scorching on the heater relay board	✅ Recommended replacement	Common failure mode
Pre-2009.5 Hot Spring / Tiger River / Limelight spas	❌ Use the 77119 instead
Post-2012.5 Hot Spring spas with IQ2020 Eagle (76836) control box	❌ Different generation — consult authorized Hot Spring dealer
Any non-IQ2020 control system	❌ Not compatible
Use as a standalone controller or motherboard replacement	❌ This is a heater relay sub-board only — it does not control pumps, lights, or other accessories

This board is designed for:

• Factory OEM replacement of failed 77118 or obsolete 76071 heater relay boards
• 2009.5 – 2012.5 Hot Spring, Tiger River, and Limelight spa heater relay service
• IQ2020 Orca / Invensys control box repair
• Both 50 Hz and 60 Hz installations (works in all countries per Orca 50/60 designation)

❓ Frequently Asked Questions

Q: How do I know if my spa needs the 77118 or the 77119? A: The two boards are for different IQ2020 control box generations. The 77118 is for 2009.5–2012.5 spas with the Orca / Invensys control box system. The 77119 is for the earlier 2001–2009.5 IQ2020 control box (pre-Orca design). Open your IQ2020 control box and check the model year and circuitry style, or contact Parts4Tubs with a photo before ordering.

Q: My existing heater relay board says “76071.” Will the 77118 replace it? A: Yes. The 77118 is the direct factory supersession for the obsolete 76071. Install the 77118 exactly the same way you would have installed the 76071.

Q: What are the failure symptoms that indicate the 77118 is the right part? A: The two primary symptoms are: (1) inside the IQ2020 control box, the red HTR ON LED is lit but no voltage is reaching the heater element across both hot leads, and/or (2) the existing heater relay board shows burn marks / charring on the front or backside. Either symptom indicates the heater relay board has failed.

Q: Can I just bypass the heater relay board? A: No. The two relays on this board provide redundant safety switching for the heater element. Bypassing them creates a serious fire hazard and voids any remaining warranty.

Q: Does the 77118 work on 50 Hz? A: Yes. Per the “Orca 50/60” product designation, this board works in all countries, on both 50 Hz and 60 Hz supply frequencies.

Q: Does the 77118 include installation hardware? A: The 77118 ships as the heater relay PCB itself. Reuse the existing screws and mounting hardware from your old 76071 or failed 77118 unless instructions from an authorized dealer specify otherwise.

Q: Will my existing temperature thermistors still work? A: Yes — thermistors and the heater relay board are separate components. However, thermistors do wear over time; if your spa is from this era, it’s common to replace thermistors (79005 / 79006 for the new style, or 39525 / 39530 for older styles with side ports) at the same time as a preventive measure. Thermistors are sold separately.

Q: Do I need a licensed electrician or Hot Spring technician to install this? A: Hot Spring / Watkins Wellness owner manuals specify that all servicing be performed by qualified service personnel. Additionally, NEC Article 680 and most local codes require a licensed electrician for any spa/hot-tub electrical work. High voltage is present inside the IQ2020 control box.

Q: My spa is a 2013 or newer Hot Spring. Will this board fit? A: Likely not. Starting around 2012.5, Watkins transitioned to the IQ2020 Eagle control box (76836), which uses different heater relay architecture. Contact Parts4Tubs with your spa’s exact model year before ordering.

Q: Is this an OEM or aftermarket board? A: This is a genuine Watkins Wellness OEM factory replacement board. Watkins Wellness is the manufacturer of Hot Spring, Tiger River, Limelight, and Caldera spa lines.

Q: Can I return it if it turns out I needed a different part? A: ⚠️ No. Spa electrical boards are non-returnable — they cannot be resold as new once installed or powered on. Please verify compatibility carefully before purchase, and contact Parts4Tubs with your spa’s model and year if you are unsure.

🏆 Why Choose the Watkins 77118

• ✅ Genuine Watkins Wellness OEM — current factory-production heater relay board
• ✅ Direct factory supersession of the obsolete 76071
• ✅ Two redundant relays for safe heater switching
• ✅ Specifically designed for the Orca / Invensys IQ2020 control box (2009.5–2012.5)
• ✅ 50 Hz / 60 Hz compatible — works in all countries
• ✅ Alternate P/Ns 3-60-0008 and reference 1310801-2 also identify this part
• ✅ Covers three major Watkins Wellness spa brands: Hot Spring, Tiger River, and Limelight
• ✅ Industry-standard failure diagnostic pattern (HTR ON LED + no heater voltage) identifies this part reliably
• ✅ Backed by Watkins Wellness’s factory warranty terms through point of purchase

🇺🇸 Why Buy From Parts4Tubs

• ✅ US-based company with local technical support
• ✅ Fast US shipping
• ✅ Expert advice from spa specialists — we’ll help you confirm whether your IQ2020 control box is the Orca/Invensys version (77118) or the earlier version (77119) before you order
• ✅ Competitive pricing on genuine OEM Watkins Wellness parts
• ✅ Factory warranty support through authorized channels
• ✅ Compatible thermistors (79005, 79006, 39525, 39530), control boxes (77087, 77271, 76836), and related IQ2020 parts in stock
• ✅ Help identifying whether you need a heater relay board replacement (this part) or a full control box replacement

✨ Summary

The Watkins / Hot Spring IQ2020 Heater Relay Board, Orca 50/60 (P/N 77118) is the current factory-production OEM replacement heater relay sub-board for Hot Spring, Tiger River, and Limelight spa models built between 2009.5 and 2012.5 using the Orca / Invensys IQ2020 control box. It directly supersedes the obsolete 76071 and is also referenced as 3-60-0008 / 1310801-2. Two relays provide safe, redundant switching of line voltage to the spa’s heater element under motherboard command. Not a standalone controller — the board installs inside an existing IQ2020 control box. Classic failure symptoms: HTR ON LED lit with no voltage to the heater element, or visible charring on the existing heater board. Works on both 50 Hz and 60 Hz systems. Non-returnable — verify that your spa uses the 2009.5–2012.5 Orca/Invensys IQ2020 (not the earlier 2001–2009.5 variant, which uses the 77119) before purchase.

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.