Technical Note: Cold commissioning process for Thermino products

(D0114)

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1. Introduction

1.1 General

The following instructions provide guidance for the installer and end-user of Thermino® Heat Batteries when installing and commissioning them under cold climate weather conditions. Additional precautions and commissioning steps must be followed to prevent premature damage or failure of the Heat Battery. Once the cold commissioning procedure has been completed, please follow the remaining standard commissioning procedure steps outlined in the respective Installation and User Instructions Manual included with the purchased Sunamp product.

These instructions must be read in conjunction with the Installation and User Instructions Manual for the purchased Thermino product:

• Thermino ePlus – document D0083 (UK/EU), D0100 (US/CA)

• Thermino xPlus – document D0084 (UK/EU), D0101 (US/CA)

• Thermino TS – document D0102 (UK/EU), D0063 (US/CA)

1.2 Symbols Used

1.3 Abbreviations

The following abbreviations are used throughout the document:

• LED = Light Emitting Diode

• PPE = Personal Protective Equipment

• S/N = Serial Number
  
  

2. Safety

2.1 General Safety Notices

3. Cold Commissioning Process

CAUTION

The Cold Commissioning Process must be followed if the Heat Battery was either stored or transported in ambient temperature conditions below 0°C (32°F) for more than 24h prior to installation.
This can be determined by briefly powering ON the appliance and observing the LED behaviour (where applicable).

DO NOT fill, vent or purge any pipes before this commissioning process has been completed first!

Figure 1 – Thermino ePlus & xPlus Heat Battery LEDs (1 to 4 left to right)

Please follow the product-specific cold commissioning instructions below:

3.1 Thermino ePlus & xPlus

1. Place the Heat Battery indoors, and leave the appliance for a minimum of 24h to come up to ambient room temperature

2. Remove the Heat Battery’s outer packaging

3. Remove the top lid and bottom cover plate by unfastening the M5 screws

4. Remove the controller ‘snap-fit’ lid

5. Inspect the Heat Battery outer case and inside of the controller for presence of any moisture, condensation or frost. If present, wait until completely dry or a further 24h (whichever is first)

6. Gently wipe down any remaining moisture with a clean cloth

7. Replace the wiring cover plate at the bottom of the unit

8. Remove the charge link (jumper cable) from terminals 1 & 2 “orange block connectors” (if present) from the terminal strip

3.1.1 For products with S/N starting from 34693

9. Wire the unit electrically as per instructions in section 6.4 of the Installation & User Instructions Manual and pay attention to the LED sequence behaviour for further instructions (see Table 1):

LED display behaviour	Description	Further instructions
	LED 3 is flashing green continuously means that either the temperature sensor string may be faulty or internal temperature of the Heat Battery is too cold	Switch OFF power to the appliance and disconnect it from the mains supply. Ensure the temperature sensor string is properly inserted into the sensor pocket. Re-power the appliance and wait for LED behaviour to begin. If LED 3 flashing continues, please contact Sunamp customer service
	All LEDs simultaneously flashing for 20s means that an internal temperature of T<0°C (32°F) has been detected upon Heat Battery initialisation	This indicates that the appliance has been exposed to temperatures below freezing, and as such, the cold commissioning procedure must be followed. Wait for flashing to stop and next mode to activate
	LED 4 is solid green and LED 1 is cycling ON/OFF every 4 minutes means that the Heat Battery is in freeze protection mode	Wait for freeze protection mode to complete and next mode to activate
	LED 4 is solid green and LED 1 is NOT lit. This means Normal operation mode of the Heat Battery is now ready	Continue Cold commissioning process from step 10 below

Table 1 – Thermino ePlus/xPlus (from S/N 34693) Heat Battery LED flashing sequence summary

10. Switch OFF the power to the Heat Battery and disconnect it from the mains supply

11. If originally present, re-insert the charge link (jumper cable) in terminals 1 & 2 “orange block connectors” on the terminal strip

12. Replace the controller ‘snap-fit’ lid, and the top lid by re-fastening the M5 screws

13. Proceed with the standard commissioning process (section 7) outlined in the Installation & User Instructions Manual provided with the Sunamp product

3.1.2 For products with S/N before 34693

WARNING

Appropriate PPE must be worn when re-inserting or removing the charge link (jumper cable) from terminals 1 & 2 “orange block connectors” from the terminal strip. Terminals 1 & 2 are VOLT FREE, however there is still risk of electric shock whilst the Heat Battery is energised!

9. Wire the unit electrically as per instructions in section 6.4 of the Installation & User Instructions Manual and pay attention to the LED sequence behaviour for further instructions (see Table 2):

LED display behaviour	Description	Further instructions
	LED 4 is flashing green continuously means that either the temperature sensor string may be faulty or internal temperature of the Heat Battery is below freezing	Switch OFF power to the appliance and disconnect it from the mains. Carefully remove the temperature sensor string from the pocket and place it on top of the Heat Battery (for 5 minutes). Re-power the appliance and wait for LED behaviour to begin. If LED 4 flashing continues, please contact Sunamp customer service. If LED 4 flashing stops, insert charge link (jumper cable) in terminals 1 & 2 “orange block connectors” of the terminal strip. Leave the unit running for 5 minutes and then remove CL for 5 minutes, repeating this procedure 3 times. Switch OFF the unit, carefully re-insert the temperature sensor string inside the temperature sensor pocket (until the yellow/white marker is at the top of the sensor pocket), and re-observe LED 4 behaviour. If flashing continues, please repeat the procedure from step 9.
	If LED 4 is solid green, this means that Normal operation mode of the Heat Battery is engaged	Turn OFF power and disconnect appliance from the mains supply. If originally present, re-insert the charge link (jumper cable) in terminals 1 & 2 “orange block connectors” and proceed with step 10

Table 2 – Thermino ePlus/xPlus (before S/N 34693) Heat Battery LED flashing sequence summary

10. Proceed with the standard commissioning process as per the Installation & User Instructions Manual provided with the Sunamp product

3.2 Thermino TS

1. Place the Heat Battery indoors, and leave the appliance for a minimum of 24h to come up to ambient room temperature

2. Remove the Heat Battery’s outer packaging

3. Remove the top lid by unfastening the M5 screws

4. Inspect the Heat Battery outer case and internals for presence of any moisture, condensation or frost. If present, wait until completely dry or a further 24h (whichever is first)

5. Gently wipe down any remaining moisture with a clean cloth

6. Measure the inlet temperature of the mains water. If temperature is minimum 5°C (41°F), follow step 7. Otherwise, follow step 8.

7. Fully open any hot water tap or shower that delivers the highest flowrate in the dwelling for 30 minutes to fully vent and fill the pipes to bring the Heat Battery to ambient temperature

8. Leave the Heat Battery for a further 48h to come up to ambient temperature, then proceed with step 7

9. Proceed with the standard commissioning process as per the Installation & User Instructions Manual provided with the Sunamp product

NOTICE

When the correct cold commissioning procedure for the Thermino product has been completed in full, please proceed with the standard commissioning process as per the Installation & User Instructions Manual (section 7) provided with the product.

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Document Part Number: D0114

Version Number: 1.0

Publication Date: 13.10.2025