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How To Connect A Heatmiser IQ+ Controller

Heatmiser IQ+

This document will explain how to connect a Heatmiser IQ+ controller to a warm air heater.
One of the most common questions we receive regarding the Heatmiser IQ+ Controller is how to correctly wire the unit to operate with a warm air heater, so hopefully this will help with the basics.

Click on the pictures to see a full size image.

Heatmiser IQ+ Wiring Diagram
Wiring Diagram

First go ahead and firmly mount the unit to a flat surface at the desired location. We generally remove the PCB from the enclosure whilst mounting the unit to prevent damage, retain the screws carefully.

Install a run of 7-Core SY flexible armored cable between the heater and the controller. We use cores sized at 1.5mm csa which is suitable for most applications and the relay rating inside the IQ+. Use the correct glands to terminate the cable correctly and pick up a cross bond to the earth tag as required.

If you bring the power supply to the IQ+ from the heater, adjust the wiring to the L and N terminals (1 & 2) as necessary, don’t forget to install a fused spur for the controller.

First we will install the power supply to the Heatmier IQ+ from the fused spur. Wire from the spur to the terminals marked Live, Earth and Neutral at the bottom of the controller board.

We need to install a couple of jumper wires inside the controller to make things work. Jumper from the incoming Live terminal and pick up one terminal each of Relay 1, 2 and 3. Make the links carefully and fully open the cages to the terminals. Use a pair of long nose pliers to push the wires fully home, with some care they will fit correctly.

Next jumper from the incoming Neutral terminal to pick up the Lockout Neon and then to the C (Common) terminal for the relay. This Neutral connection to the relay assumes that the lockout signal requires N to be applied to re-set the control box so check first. All the equipment we install uses N lockout!

Core 1 – Live feed to the heater so wire this directly into the Live output of the spur.
Core 2 – Neutral feed to the heater, again wire this from the Neutral output of the spur.
G/Y – This is the earth cable which should be wired to the Earth terminal of the spur.
Core 3 – This provides the signal to the heater to provide “Heat”.
Core 4 – This provides the signal to the heater to turn the “Fan” on only.
Core 5 – This provides a Live signal from the heater to the control box to signal it has locked out.
Core 6 – This provides a Neutral signal from the controller to the heater control box to pull it out of lockout.

Wire the remaining cores into the heater to correspond to the relevant terminals.

Powrmatic heaters are well labeled. Click on the pictures below to see wiring connections for Powrmatic and Benson.

Heater Wiring Diagrams
Wiring Terminals To A Powrmatic NVx Heater

Wiring Connection Terminals