Phase change
Our cells hold a salt hydrate that melts at 58°C. While it melts, it soaks up a large amount of energy without getting much hotter, so the store stays compact and loses less heat. Freezing gives that energy back at a steady temperature.
Technology
A heat store that reads the tariff.
Three modules in one cabinet: controls that decide when to buy power, a store of phase-change cells that holds it as heat, and the hydraulics that deliver it to your radiators and taps. No flame, no flue, no gas supply.
Store
58°C melt
Loss
<3% a day
Cycles tested
10,000
Fig. 2
Exploded view
01A day in the life
Watch a cold day go by.
Slide through 24 hours on an illustrative time-of-use tariff. The green line is how full the store is; the ochre line is the price of electricity. Shaded bands are the cheap hours.
The day chart needs JavaScript.
00:0012:0023:30
- Half hour
- 17:30–18:00
- Price
- 34p / kWh
- Store
- –
- Heat to home
- –
- Mode
- ReleasingPeak or day rate: the radiators and taps are fed from the store.
Over this cold day the Heatloop 28 buys most of its electricity at the cheap rate.
Modelled for a home using 46 kWh of heat on a cold day. The tariff is illustrative; your Heatloop follows the real prices of the tariff you choose.
02Inside the store
Most of the energy hides in a melt, not a temperature.
Vacuum-panel walls
Twenty millimetres of vacuum insulation panel lines every face of the store. In our lab tests a full Heatloop 28 loses less than 3% of its heat in a day, and that heat leaks into the room it stands in. Figures for other stores are typical values for comparison.
Controls that plan ahead
Each evening the controller reads tomorrow’s prices, the weather forecast and how your home used heat last week, then plans when to charge. Comfort always comes first: if the store runs low, it heats directly.
03Specifications
Three sizes, one design.
Indicative prices include installation, before any grants. The final price is confirmed after a free home survey.
| Heatloop 18 | Heatloop 28 | Heatloop 40 | |
|---|---|---|---|
| Suits | Flats and small terraces | Most terraces and semis | Detached and larger homes |
| Heat stored | 18 kWh | 28 kWh | 40 kWh |
| Charging element | 5 kW | 7 kW | 9 kW |
| Heat output | up to 12 kW | up to 16 kW | up to 20 kW |
| Hot water | up to 18 l/min | up to 22 l/min | up to 26 l/min |
| W × D × H | 600 × 600 × 1150 mm | 600 × 600 × 1650 mm | 750 × 600 × 1850 mm |
| Weight, full | 210 kg | 320 kg | 450 kg |
| Supply | 32 A single phase | 40 A single phase | 45 A single phase |
| Noise | Under 30 dB(A) at one metre, a quiet pump and nothing else | ||
| Warranty | 10 years on the store, 5 years on controls and hydraulics | ||
| Indicative price | £4,900 | £6,400 | £8,200 |
| Reserve | Reserve a Heatloop 18 | Reserve a Heatloop 28 | Reserve a Heatloop 40 |
04Good questions
What engineers and neighbours ask us.
Is it the same as a storage heater?
No. A storage heater warms one room and leaks its heat whether you want it or not. A Heatloop sits in a cupboard or utility room, keeps its heat until it’s asked for, and feeds a whole wet heating system and your hot water.
Will it work with my radiators?
It delivers water at up to 62°C, which most radiator systems sized for a boiler handle well, especially with modern controls. Our survey checks your radiators and tells you honestly if any would need upgrading.
What happens if the store runs out?
The element heats water directly, like an electric boiler, so you are never left cold. You pay the price of the moment for that heat, which is why the controller plans to avoid it.
Is the material inside safe?
The salt hydrate is non-flammable and sealed in welded cells inside a steel case. Nothing burns, and there is no combustion gas in your home. We are working through product certification with an independent test house and will publish the results.
Do I need a special tariff?
You’ll get the most from a tariff with cheap hours, such as a smart time-of-use tariff or Economy 7. On a single-rate tariff a Heatloop still works, but there is nothing cheaper to shift to. The estimator shows the difference.