How does eddi work with a heat pump?

With the introduction of new incentive schemes, general publicity and new Building Regulations, heat pumps are becoming increasingly popular for heating our homes across Ireland. In Ireland alone there are a reported 57,200 households benefiting from air source heat pump technology. This is largely due to homeowners wanting to reduce energy bills by replacing old oil boilers or electric heating systems.

Our power diverter, eddi, can be installed alongside a heat pump to enhance the savings customers can achieve by maximising self-consumption of microgeneration.

What is a heat pump?

For homes already off, or wanting to be off, the gas grid, heat pumps are a great electric alternative to heating your home with gas. The most popular heat pump in the UK is a monobloc air source heat pump, which sits outside your home and connects to your homes central heating pipework to heat your radiators.

Just like a fridge, a heat pump uses electricity to run a compressor which will compress gas that has been heated by the outside temperature to higher temperatures, before transferring the heat to your radiators. This is what results in the 300% efficiency, or commonly known as coefficient of performance (CoP) of 3.0.

Because of this, heat pumps are growing in popularity as they significantly reduce the costs of heating a home with electricity compared to traditional electric heating.

What are the benefits of using eddi with my heat pump?

Divert even the smallest amounts of surplus

eddi will charge your hot water no matter the PV generation meaning you are using any remaining excess the heat pump doesn’t use.

Choose how you heat your water

With eddi you have the ability to heat your water tank using your heat pump or an immersion heater.

Smart switching between heaters

eddi can automatically switch between heaters based on your excess generation/ export.

Manage and monitor your home’s energy

Set hot water schedules, and gain full visibility of how much energy you are using to heat your home, using the myenergi app.

Control your water temperature

Using a thermistor sensor (PTC) you can view the exact temperature of your tank and set your preferred maximum temperature.

Schedule protection cycles

Use eddi or your heat pump to schedule regular legionella protection cycles.

Can I use eddi with any heat pump?

Yes, you can use your eddi with any heat pumps that support SG-Ready (Smart Grid), or that have a dedicated hot water enable connection. If you heat pump was installed after 2012 SG-ready. To help you check if eddi is compatible with your heat pump, or to find a heat pump that works with eddi, we’ve named a few market-leading heat pumps.

For the full database inc individual model numbers see Heat Pump Database

Manufacturer	Models	Compatible
Vaillant	aroTHERM aroTHERM Split aroTHERM Plus flexoTHERM
Samsung	EHS TDM Plus NEW ONE
Mitsubishi	Ecodan R410A & R32
Daikin	Altherma Mono Altherma Split R410a & R32
Panasonic	Aquarea All in One Aquarea High Performance
Grant UK	Aerona
LG	Therma V
Midea	M Thermal R32 Monobloc

How does eddi divert my excess generation to my heat pump?

When fitted with the optional relay board eddi has a lot of functions, one of the most beneficial functions is to enable a heat pump when a certain amount of generation/export has been detected.

You can do this so that the hot water tank (immersion heater) will heat when generation is low (for example less than 2kW) and then once higher generation is available (in this case above 2kW) you can have eddi activate the heat pump in domestic hot water, so you know you are covering all, or a large majority, of the heat pumps power requirements and getting more from your PV generation.

How can I control my water temperature with eddi?

With SG-Ready heat pumps you can utilise the in-built hot water timer to control your hot water schedule, as well as to set a desired hot water temperature. In the heat pump controller, you have the ability to set the PV offset which eddi can enable. We recommend setting this to 75°C only if a suitable blending valve is available to prevent scolding risk. If you are unsure if a blending valve has been fitted, instead use 60°C and consult a competent heating engineer to confirm a blending valve has been fitted before increasing.

With this configuration the heat pump can be used to provide an initial charge overnight to a minimum temperature, ensuring that when surplus is available the tank can be charged to a higher temperature, using solar or wind electricity generation.

We recommend fitting a PT1000 sensor to your hot water tank for improved visibility of the tank temperatures within eddi and the myenergi app.

How do I install an eddi?

For this installation you will only need to utilise one of the relays on the relay board that will be connected to the SG-Ready “Switch On Recommendation” or PV Ready connection for activation of hot water boost mode for solar PV. These connections vary by heat pump manufacturer so please consult the manufacturers installation manual.

Settings required

Device Settings > Advanced -> Relay & Sensors -> Relay 1 -> Export -> On Threshold

We’ve provided our recommended settings ‘On Threshold’ for general heat pumps, for targeting 100% coverage or 50% coverage of heat pump electricity requirements from solar power.

Heat Pump Size	COP 2.5 for 100% coverage	COP 2.5 for 50% Coverage
5kW	2kW	1kW
8kW	3.2kW	1.6kW
10kW	4kW	2kW
12kW	4.8kW	2.4kW
15kW	6kW	3kW
20kW	8kW	4kW