Technical Note: Thermino ePlus/xPlus & Volt-Free timer wiring instructions
(D0109)
NOTICE
Please read & comply with all these instructions before commencing installation. Failure to install and operate this system in accordance with these instructions will invalidate the manufacturer’s warranty.
Please leave these instructions with the customer for future reference.
Always use these instructions in conjunction with the Installation and User Instructions Manual of the purchased Sunamp heat battery.
1. Introduction
1.1 General
The following instructions provide guidance for installing suitable volt-free timers and time switches to control the electric charging demand of Thermino® ePlus and xPlus heat batteries. These instructions must be read in conjunction with the Installation and User Instructions Manual for the Thermino ePlus (D0083) and xPlus (D0084) products.
WARNING
All installations must be carried out by a competent installer in accordance with local codes and regulations for plumbing, electrical installations and potable water supply.
1.2 Symbols Used
In these instructions the following symbols are being used to draw the user’s attention to information of particular importance.
WARNING
Indicates a hazardous situation that, if not avoided, could result in death or serious injury.
CAUTION
Indicates a hazardous situation that, if not avoided, could result in minor or moderate injury or material damage.
NOTICE
Signals information that is considered important but not hazard related.
2. Safety
2.1 General Safety Notices
WARNING
Only competent persons suitably qualified to carry out plumbing and electrical work may undertake installations, repairs or relocations of the appliance.
Product training on the full range of Thermino heat batteries is available from Sunamp or authorised training partners.
WARNING
Risk of electric shock – potential dual supply. Always isolate the power supplies to the heat battery controller before working on the heat battery.
CAUTION
These instructions must be read in conjunction with the Installation and User Instructions for the respective Thermino product.
CAUTION
Do not operate the immersion heater until the correct commissioning procedure has been identified and the unit has been appropriately commissioned (see document D0114).
3. Volt-Free timers & Thermino wiring
CAUTION
If switching the live supply to the Heat Battery’s integrated heating element, please refer to the Thermino ePlus andxPlus with PV wiring and settings manual (D0085) for permanent and switched supplies wiring instructions.
Switching the supply to the immersion heater requires timers that can switch the following minimum resistive loads:
(i) 16A for Thermino products fitted with a 2800W heating element,
(ii) 10A for Thermino products fitted with a 1800W heating element.
CAUTION
The instructions included in this document are relevant for VOLT-FREE timers/time switches only, and must not be used for switching live supplies!
NOTICE
A suitable timer/time switch is one that provides a volt-free/dry contact signal, and must be wired in accordance with the manufacturer’s instructions and local wiring codes and regulations.
The below wiring diagrams show how suitable volt-free timers/time switches must be wired to Thermino ePlus and xPlus Heat Batteries. Please refer to the timer-specific sections below for more detailed information on timer wiring instructions.
3.1 Thermino ePlus wiring
Figure 1 - Thermino ePlus with volt-free time switch
3.2 Thermino xPlus wiring
Figure 2 - Thermino xPlus with Back-up volt-free time switch
NOTICE
The intended use of Thermino xPlus products is to be charged by external heat sources as the primary source of energy. For more information on how to access back-up electric mode in Thermino xPlus products, and the circumstances under which it is permitted, please refer to document D0093.
4. Volt-Free timer wiring instructions
4.1 Optimum timeswitch wiring instructions
TFC group manufacture a range of OPTIMUM Wi-Fi time switches that are suitable for use with Thermino products. These time switches are listed below:
OP-SBWF01 Wi-Fi Socket Box Timer
OP-BM-IHTWF01 Wi-Fi Boiler Module
NOTICE
If installed, the above time switches must be wired to Thermino ePlus/xPlus heat batteries as shown in Figures 1 & 2, and follow the wiring guidance in the table below. For detailed information on installation instructions and Wi-Fi comms set-up, please refer to the manufacturer’s user and installation instructions.
Timer Model |
Notes |
OP-SBWF01 |
Terminals “3” & “4” on the time switch need to be wired to the orange block terminals “1” & “2” on the heat battery’s controller terminal strip. Note: Please remember to remove the charge link (bridge link) if present in orange block terminals “1” & “2”! |
OP-BM-IHTWF01 |
The brass link between terminals “2” & “3” on the OPTIMUM time switch must be removed. Terminals “2” & “3” on the time switch need to be wired to orange block terminals “1” & “2” on the heat battery’s controller terminal strip. Note: Please remember to remove the charge link (bridge link) if present in orange block Terminals “1” & “2”! |
Table 1 – OPTIMUM time switch wiring instructions
4.2 Timeguard time switch wiring instructions
Timeguard manufacture a time switch that is suitable for use with Thermino products. This time switch is listed below:
NTT04 – 24 Hour/7 Day Compact Electronic General Purpose Timeswitch with Voltage Free Contacts
NOTICE
If installed, the above time switches must be wired to Thermino ePlus/xPlus heat batteries as shown in Figures 1 & 2, and follow the wiring guidance in the table below. For detailed information on installation instructions, please refer to the manufacturer’s user and installation instructions.
Timer Model |
Notes |
NTT04 |
Terminals “S OUT” & “S IN” on the time switch need to be wired to orange block terminals “1” & “2” on the Heat Battery’s controller terminal strip. Note: Please remember to remove the charge link (bridge link) if present in orange block terminals “1” & “2”! |
Table 2 – Timeguard time switch wiring instructions
NOTICE
For detailed wiring, hydraulic installation and commissioning instructions, please refer to the heat battery Installation & User Instructions manual.
Document Part Number: D0109
Version Number: 1.0
Publication Date: 30.04.2025
Sunamp Ltd
1 Satellite Park
Macmerry
East Lothian
EH33 1RY
Scotland
Customer Service (Phone): +44 (0)1875 610 001
Customer Service (Email): customerservice@sunamp.com
www.sunamp.com