The tepeo ZEB (Zero Emission Boiler) is an electric heat battery that replaces a gas or oil boiler. It charges using electricity, ideally during cheaper off-peak periods, stores that energy as heat inside the unit, then releases it to your radiators, underfloor heating and hot water cylinder when the thermostat calls for heat. There’s no combustion and no emissions at your home.
It tends to suit homes with an existing wet heating system that want to move away from gas or oil but aren’t a good fit for a heat pump, and that can use an off-peak electricity tariff. Our tepeo ZEB page explains how we assess and install them.
How a heat battery boiler works
A standard electric boiler heats water instantly from live electricity, so it draws power whenever the heating is on, including at peak times. The ZEB works differently:
- It charges gradually from the grid, typically when electricity is cheaper
- The energy is stored as heat in a thermal store inside the unit
- When heat is needed, it’s released into the wet heating system
This means you can use stored, cheaper electricity during the day and evening instead of paying peak rates.
Which homes it suits
A ZEB may be a good option if you:
- Want to replace a gas or oil boiler
- Have radiators or underfloor heating fed by a wet system
- Can’t install a heat pump, for example due to space, noise concerns or planning restrictions
- Can access an off-peak or time-of-use electricity tariff
- Want zero on-site emissions
It may be less suitable if the home has very high heat demand, or if the electrical supply can’t support the unit. A professional assessment is needed to confirm.
ZEB vs heat pump vs standard electric boiler
| tepeo ZEB | Air source heat pump | Standard electric boiler | |
| Heat source | Stored electric heat | Heat from outside air | Live electricity |
| Outdoor unit | No | Yes | No |
| Uses off-peak electricity | Yes, by design | Can, with smart tariffs | Not by design |
| Efficiency | Similar to direct electric | Generally much higher per kWh | Similar to direct electric |
| Radiator changes | Usually minimal | Often some upsizing | Usually minimal |
| Emissions at home | None | None | None |
A heat pump is usually the most efficient low-carbon option where the home suits it. The ZEB’s advantage is that it can work with existing radiators and doesn’t need an outdoor unit, so it fills a gap for homes where a heat pump isn’t practical. You can compare the options on our heat pumps and electric boilers pages.
Running costs: what they depend on
Running costs depend on:
- Your off-peak electricity rate and how much of your heat comes from it
- The heat demand of your home (size and insulation)
- How the system and controls are set up
- Whether you have solar panels
Because it’s still electric heating, a ZEB won’t be as cheap to run as a well-designed heat pump in a suitable home. Compared with a standard electric boiler, the ability to charge off-peak can make a real difference, depending on the tariff.
Questions to ask before choosing a ZEB
- What’s the heat demand of my home, and is the ZEB sized for it?
- Can my electrical supply support the unit?
- Which off-peak tariff would suit me?
- Will my existing radiators and cylinder work with it?
- What maintenance and warranty come with it?
ZEB installations around Surrey and South West London
Many homes around Epsom, Kingston, Worcester Park and Richmond are flats, terraces or houses with limited outdoor space, where a heat pump can be tricky. That’s where a heat battery can be worth considering as an alternative way off gas.
Frequently asked questions
Does the tepeo ZEB provide hot water?
Yes. It releases heat to a hot water cylinder as well as to radiators or underfloor heating.
Does a ZEB need a flue?
No. There’s no combustion, so no flue or gas supply is needed.
Can a ZEB work with solar panels?
It may be possible depending on the property setup. Your installer can advise on how solar and battery charging would work together.
Does the ZEB need servicing?
It doesn’t need a gas safety check, but periodic maintenance is sensible. Ask your installer about the manufacturer’s recommendations and warranty terms.
Wondering if a ZEB would work in your home?
If you’re thinking of moving off gas or oil, give us a call on 020 8394 2776 or drop us a message and we’ll come and take a look and talk you through it.