Harvia Fenix Controller Installation Guide
Bypassing the Heater Control Panel for Use with a Harvia Fenix Control System
⚠️ Licensed Electricians Only
This procedure involves modification of the factory electrical controls within a Harvia sauna heater.
This work must only be carried out by a licensed electrician in accordance with local electrical regulations and Harvia installation requirements.
Failure to perform this procedure correctly may result in:
- Electric shock
- Fire
- Equipment damage
- Heater malfunction
- Voided warranty
- Non-compliant installation
Always isolate and verify power is disconnected before commencing work.
Overview
Many Harvia heaters are supplied with built-in:
- Thermostat controls
- Mechanical timer controls
When installing a Harvia Fenix Control System, these factory controls must be removed from the heating circuit.
This guide explains how to remove the original control system and prepare the heater for operation with a Harvia Fenix controller.
Before You Start
Tools Required
- Insulated screwdrivers
- Cordless drill/driver
- Multimeter
- Camera or phone
- PPE
Safety Checks
✅ Turn power OFF at switchboard
✅ Lock out if required
✅ Verify heater is de-energised
✅ Allow heater to cool completely
Step 1 – Remove Sauna Stones
Purpose: Gain access to the heating elements and internal wiring.
Procedure
- Remove all sauna stones from the heater.
- Place stones aside for reinstallation later.
- Inspect elements for damage.
📷 Insert Image: Heater with stones removed
Step 2 – Remove Control Knobs
The factory timer and thermostat knobs must be removed before the control assembly can be accessed.
Procedure
- Pull off the thermostat knob.
- Pull off the timer knob.
- Retain for disposal with the control assembly.
📷 Insert Image: Close-up of control knobs before removal
Step 3 – Remove Internal Control Assembly
The thermostat and timer assembly will now be removed from the heater.
Procedure
- Open the control compartment.
- Remove retaining screws.
- Carefully withdraw the timer and thermostat assembly.
The entire assembly shown below will no longer be required once the heater is controlled by the Fenix controller.
📷 Use Image: White timer/thermostat assembly removed from heater (IMG_3111)
📷 Use Image: Assembly being lifted from heater (IMG_3113)
Step 4 – Identify Existing Terminal Block Wiring
Before disconnecting anything:
Important
Take multiple photos for reference.
The original Harvia heater uses:
- Three black conductors
- Three blue conductors
These wires connect the:
Terminal Block → Timer/Thermostat → Heating Elements
📷 Use Image: Original terminal block wiring (IMG_3108)
📷 Use Image: Original wiring overview (IMG_3099)
Step 5 – Disconnect Element Wiring
Disconnect all element conductors from the thermostat and timer assembly.
Procedure
- Locate all black and blue conductors connected to the control assembly.
- Remove conductors from timer and thermostat terminals.
- Leave heating element terminals accessible.
📷 Use Image: Electrician disconnecting wires (IMG_3106)
📷 Use Image: Element wiring exposed (IMG_3105)
Step 6 – Remove Factory Control Wiring
The original control circuit is now removed.
Remove
- 3 × Black conductors
- 3 × Blue conductors
These wires are no longer required when using a Fenix controller.
After removal, the heater should resemble the image below.
📷 Use Image: Wiring removed from terminal block (IMG_3100)
📷 Use Image: Terminal block cleared (IMG_3092)
Step 7 – Connect Heating Elements Directly to Terminal Block
The heating elements must now be connected directly to the terminal block.
Objective
Remove:
Timer → Thermostat → Elements
Replace with:
Fenix Controller → Terminal Block → Elements
Procedure
- Connect element conductors directly to the terminal block.
- Install:
- Three black conductors
- Three blue conductors
- Ensure all connections are tight and secure.
📷 Use Image: Blue conductors being installed (IMG_3107)
📷 Use Image: Black conductors connected (IMG_3101)
📷 Use Image: Wiring arrangement completed (IMG_3102)
Step 8 – Connect Incoming Supply Conductors
The Fenix controller wiring can now be terminated at the heater.
Follow the Harvia wiring diagram supplied with the Fenix control system.
Typical Connections
- L1
- L2
- L3
- Neutral
- Earth
⚠️ Verify conductor positions against the specific heater model and Fenix wiring diagram.
📷 Use Image: Incoming cable connected (IMG_3103)
📷 Use Image: Completed terminal block (IMG_3114)
Step 9 – Verify Wiring Against Harvia Diagram
Before energising:
Confirm all wiring matches the factory diagram.
📷 Use Image: Wiring diagram label (IMG_3110)
Check
✅ Terminal positions
✅ Earth continuity
✅ Tightness of all terminals
✅ Insulation resistance
✅ Correct phase allocation
Completed Installation
When complete:
Original System
Terminal Block → Timer → Thermostat → Elements
New System
Harvia Fenix Controller → Terminal Block → Elements
The heater is now fully controlled by the Harvia Fenix system.
📷 Use Image: Final completed wiring (IMG_3109)
📷 Use Image: Final overview inside heater (IMG_3097)
Final Electrical Testing
Before re-installing stones:
✅ Earth continuity test
✅ Insulation resistance test
✅ Verify phase rotation if applicable
✅ Verify contactor operation
✅ Confirm Fenix controller communication
✅ Confirm element operation
Reinstall Sauna Stones
Once testing is complete:
- Reinstall stones according to Harvia instructions.
- Do not tightly pack stones.
- Ensure airflow remains unobstructed.
The heater is now ready for commissioning with the Harvia Fenix Controller.
Recommended YouTube Video Structure
Title:
How to Bypass a Harvia Heater Control Panel for a Harvia Fenix Controller | Electrician Installation Guide
Video Chapters:
00:00 Introduction & Safety Warning
00:45 Remove Sauna Stones
01:20 Remove Control Knobs
02:00 Remove Timer & Thermostat Assembly
03:20 Disconnect Factory Wiring
05:00 Remove Black & Blue Control Wires
06:30 Connect Elements Directly to Terminal Block
08:30 Connect Fenix Controller Wiring
10:00 Final Testing & Commissioning
11:00 Reinstall Stones & Completion
At the top of the webpage, place a red warning banner:
WARNING: This procedure must only be carried out by a licensed electrician. Innerlight Sauna does not recommend or permit electrical work by unlicensed persons.
