Greenvision Energy

Tepeo Zero Emission Electric Boiler Zeb

Direct replacement for gas & oil boilers

Talk to Greenvision, award-winning, independent national electric heating experts. 

Tepeo Zeb approved installer.

Is a Zeb Zero Emission electric boiler for me?

If you want to replace an inefficient electric boiler or gas or oil central heating, then the Zeb must be considered.

It is an electric boiler with an efficient battery that charges using off-peak tariffs and can also be charged from solar PV and other renewable sources. The Zeb can store the heat efficiently thanks to high insulation levels, which locks the heat in. Thanks to intelligent management software, thermostat and timer, you choose when you want the stored heat released to your existing radiators/underfloor heating.

Zeb is a low-carbon direct replacement and alternative to gas or oil boilers  heating your home affordably while lowering your carbon footprint. There is no need to rip your house apart with the Zeb as it connects to your existing system and can be installed in 1-2 days.

We offer a free consultation to understand your requirements, we can guide you through different options, and answer any questions. Whether you are a homeowner, landlord or social housing provider sit back and relax with our award-winning installation service. We are Which and EDF Energy Approved Installers

How does the Zeb work?

The ZEB’s ‘brain’ uses machine learning and a clever algorithm to calculate how long and where to charge from (low rate tariffs, renewable sources like solar PV) based on your heat demands. Zeb is always looking to save you money, if you have solar panels installed, Zeb will utilize this free energy first before charging from the grid. It will even take into account weather conditions. Yes, it is truly smart.

The ZEB’s battery charging are(9.3kWh/h charging rate and 40kWh maximum charge). This means it is ideal for 2-3 bedroom homes. The Zeb works just like a conventional boiler with flow & return, and a heat exchanger but has a highly insulated core (battery) that optimises how heat is transferred around your system

The Benefits of Zeb

  • It’s powered by electricity and works like a battery to store 40kWh of energy as the heat really efficiently until it is needed
  • Uses the cheapest off-peak tariffs and can also charge from solar PV generation
  • Works with your existing gas/oil central heating system. No need to change your radiators
  • Unrivalled heat retention – minimises heat loss for lower energy consumption and running costs
  • WiFi-controlled heating via the Smart app. It also works with any thermostat
  • Peace of mind – 10-year guarantee.
  • State-of-the-art, compact design

More reason to install Zeb boiler

Save more energy by upgrade your existing radiators & heating controls

Old central heating radiators, Incorrectly sized radiators or radiators in the wrong position could be costing you money. By upgrading to the latest energy-efficient ones with Wi-Fi-controlled thermostatic radiator valves and a smart thermostat could save you even more money and reduce your heating bills.

Improve the efficiency of your heating system with a powerflush

A powerflush will enhance the energy efficiency of your existing heating system, potentially lower your energy bills and Improved its reliability. It can help increase hot water temperatures in your system, speed up radiator heat-up times, and reduce boiler and radiator noise.

Wi-Fi-controlled heating

Control and monitor your heating from anywhere in the world with your smartphone or tablet. Ideal if you own a second home, holiday let, Airbnb or work shifts. Also, control your heating using your voice, just say “Alexa, turn the heating on”.

Reduces your carbon footprint

The cost of heating your home is expensive and burning fossil fuel is not good for the environment. In the UK we are now generating over 50% of our energy through renewable sources. The Zeb has been designed to use cleaner energy sources which are similar in cost to gas and soon to be cheaper. From 2025 government legislation will ban the installation of gas boilers into new build properties, so there has never been a better to upgrade

FAQ's about Zeb boiler

The ZEB’s ‘brain’ uses machine learning and a clever algorithm to calculate how long and where to charge from (low rate tariffs, renewable sources like solar PV) based on your heat demands. Zeb is always looking to save you money, if you have solar panels installed, Zeb will utilize this free energy first before charging from the grid. It will even take into account weather conditions. Yes, it is truly smart.

The ZEB’s battery charging are(9.3kWh/h charging rate and 40kWh maximum charge). This means it is ideal for 2-3 bedroom homes. The Zeb works just like a conventional boiler with flow & return, and a heat exchanger but has a highly insulated core (battery) that optimises how heat is transferred around your system



Not all electricity is created equal… some electricity is cheaper than the rest and some electricity is cleaner. The price is a function of various things including how many electricity-consuming things across the network want that bit of electricity at that time - it’s basic demand and supply economics. The cleanliness is a function of the mix of generation sources that are generating electricity at the time in the area. Here at tepeo we have been exploring how to make sure we draw the best electricity in terms of cost and carbon footprint for you while at the same time making sure that your ZEB is always as charged up as it needs to be at any time to meet your household heating demand.


We have designed part of the ZEB intelligence that is located remotely to be responsible for calculating charging schedules for all our active ZEBs. It starts with the predicted hot water and heating demand for your home - we use a machine learning algorithm to predict this, having fed it a diet of your home’s historical usage and local weather data. It then looks at the weather forecast for the coming 24 hours and predicts the likely resultant heating requirement. This gives our charging algorithm the target profile of heat output to aim to be able to deliver, with the aim of keeping the charge level as low as possible at any given time.


We then overlay the following inputs associated with each ZEB:

  1. Minimum state of charge, as set by the ZEB owner, in line with their sense of a minimum amount of energy to always have on standby - e.g. this might be 5kWh - enough for a hot bath or two and to warm an extra bedroom for an unexpected guest!

  2. Cost/carbon weighting, also set by the ZEB owner, according to whether they care more about the cost, or the carbon footprint, or a bit of both.

  3. The maximum possible charging rate - this is a physical limit on the ZEB itself which is 9.3kW (or 9.3kWh per hour…) for our current model.

  4. Overall ZEB capacity - 40kWh for the current model.

Users choose how cost or carbon conscious they are

Users choose how cost or carbon conscious they are


Then we overlay the other inputs for any particular day:

  1. Electricity tariff - this may be static such as the Octopus Go tariff which is one rate for most of the day and then a cheap rate between


    , or it may be dynamic such as the Octopus Agile tariff where the half-hourly prices for the following 24 hours are published and picked up by our application programming interface every day.

  2. Carbon intensity - we currently use but there are several ways of deriving this (this is on a half-hourly basis).

  3. Spare solar production anticipated (this is specific to your house, combining local weather forecasts and historic solar performance from previous days).

  4. Export tariff

tepeo Optimisation Algo

The charging strategy is continuously monitored throughout the ZEB’s operation to ensure that your household’s heating demands are being met. On a typical day, the ZEB might be called upon by National Grid to soak up renewable generation when there is a surplus or to balance the electricity system on faster time scales. If you have solar PV installed on your roof, we will be continually tuning our predictive models in order maximise solar charging. All of this is done while making sure that you have enough hot water to have a shower when you want it, or to do the dishes when you need to do them!


In the plots below (which cover three days starting 00:00:00 24th October 2020 and ending 23:30:00 26th October 2020), we can see how a ZEB would handle negative pricing using the Octopus Agile tariff. During the early hours of 25th of October 2020, the Agile tariff became negative. We can see that the ZEB took advantage of this by charging itself to 100%. Throughout this period of three days, the ZEB also retained a base state of charge to act as a buffer for impromptu requirements for heat when needed. It is worth noting that on the 25th of October, the ZEB would have made money for the homeowner by taking advantage of negative pricing! 

ZEB Charging Graph
ZEB Heating Consumption Graph

 The ZEB? 98cm (height) x 60cm (width) x 66cm (deep) - but it needs clearance of 7cm above and 5cm either side and weighs  375kg

  • How efficient is it? When the ZEB is charged, it does become a little bit warm itself - the surface temperature is cooler than a radiator but there will be some heat losses present which will heat the area where the ZEB is located. A ZEB installed inside a home is 100% efficient however as those heat losses are still contained within the heating envelope!

    In terms of conversion of electricity into heat in the heating system only, the trial houses which hosted (and continue to host) ZEBs over the past 12 months or so have averaged 87% ± 5% (variance due to the differing patterns of heating demand between the houses and our improving algorithms).

    It is worth noting that this is higher than you are ever likely to see even from a brand new gas boiler in terms of actual real world performance.

    We are working on improving this performance, such as advising our trialists to use immersion with a timer for hot water heating rather than using the ZEB for water heating, particularly in the summer months. We will update this number as and when we have enough data to see what difference this makes.

    To be absolutely clear the ZEB converts 100% of its electricity consumption into heat which will contribute to the heating of your home. This is why for EPC purposes it is classified as 100% efficient.

A Zeb stores 40kWh of usable thermal energy

A Zeb can output 15kW maximum

Any temperature up to 80°C - your current boiler won’t be higher than this, so you will notice not difference

4 hours from empty. It can deliver heating after half an hour (from cold)

  • How long will it last? We have designed the ZEB to last 20+ years. We will include all maintenance and servicing within the management fee. Similar versions of the physical technology installed in the 60s/70s are still going strong!
  • How often will it need servicing? No routine servicing required. Our monitoring systems tell us if we need to address anything

To start your free consultation, simply complete our online form below.
If you prefer you can call us on 0115 854 7498
or email us

What people think

Based on 33 reviews
Isobel Gleave
Isobel Gleave
I'm very pleased that I went ahead and replaced my old storage heaters with the new Dimplex ones. The whole process went smoothly and efficiently and Greenvision were very helpful at all stages and didn't rush me. Apart from working better than the old ones they also look smart, as does the new bedroom panel heaters. The installers did a brilliant job and didn't leave a trace.
Gemma Rogers
Gemma Rogers
Quality service for installation of a new Dimplex Quantum storage heater, Rointe electric towel rail, updated fuse box and all associated. The service provided by Greenvision went beyond all expectations. Everyone was extremely helpful and friendly. Stuart and Paul provided professional advice based on what would be best for me. The virtual survey option was ideal, so we could discuss options and get a quote straight away, which meant from contacting Greenvision to installation was only a couple of weeks! Amanda was great in keeping me up to date about the installation and arrangements. On the day, Dan arrived exactly when expected and fitted everything perfectly, it's made such a difference. Thank you to everyone at Greenvision. Very impressed and wouldn't hesitate to recommend!
Peter Graystone
Peter Graystone
I found Greenvision very pleasant to work with. The explanation of the product, and the survey to check it was suitable for my home were both excellent. The engineer was courteous and efficient, although I would have loved it if he had vacuumed before he left. I'm very pleased on the whole.
Purchase and installation of Dimplex Quantum Storage Heaters. Very professional from start to finish. In contact throughout. Answered questions and were friendly and helpful. Fitters were very efficient and even brought a hoover to clear up afterwards! They explained everything regarding usage. Very polite and professional from start to finish. Would recommend.
ann munro
ann munro
I instigated my business with Greenvision 6 weeks or so ago. The staff at Greenvision were informative, considerate of my needs and quick to answer any queries. Adjustments to my advantage were made after a survey which have proved to be most adequate. The installation occurred on 16th. January. The engineers were on time, efficient and considerate, clearing up and tidying up as they proceeded. They took time to make sure I understood the basics of operating my heaters. I will certainly recommend Greenvision where and when I can. So quick.
Sarah Moyer
Sarah Moyer
I used Greenvision for purchase and installation of 2 electrical high heat retention heaters for use with Economy 7. Everyone at Greenvision was friendly and helpful. Although based in Nottingham they facilitated installers for me in London. The whole process was seamless, quick and efficient. I would certainly recommend this company.
Carol G
Carol G
We purchased new Dimplex storage heaters through Greenvision. I was totally impressed by their level of knowledge, advice, customer service and ability to organise an efficient installation of these products at our property in North Wales. Highly recommended!
Lucy Reynolds
Lucy Reynolds
Very pleased with the installation of a Quantum Dimplex storage heater. Clearly explained at all stages and electrician who installed it was excellent.
Ray W
Ray W
6 Dimplex Quantum storage heaters installed to replace old heaters and associated modifications carried out to wiring in meter cupboard. Friendly helpful installers and very professional job. Highly recommended.
Brian Lomas
Brian Lomas
Supplied and fitted 3 Dimplex Quantum storage heaters. Used Greenvision because other residents in our retirement flats recommended them from their experience. They were right to do so as our experience was the same. From start to finish our experience was seamless and efficient ,polite, friendly are words that come to mind. The team that arrived with us on installation day was Nathan/Paul and Luker. All three were cleanly dressed, polite and friendly but courteous. They were very competent indeed and represented an excellent image of the Company. J B and L Lomas SANDBACH