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iHeat list the 6kWh Sigenergy at £5,245, or £109 a month. Heatable print a 9.04kWh SigenStor in the quote tool. Tonight that was £6,100. Different size, and the figure moves with the postcode.
The same iHeat unit with panels is £7,845, or £163 a month. Heatable also publish 0% APR on their Sigenergy package, up to two years. There is no Boiler Upgrade Scheme money on a battery. A Tesla Powerwall 3 is £7,945 if you want the bigger public box on iHeat.
The 6kWh unit: verdict
If you want the published 6kWh figure, start with iHeat. They list the storage and inverter at £5,245, or from £109 a month. Heatable are the second number because they actually install SigEnergy. They do not publish a cash price. No BUS.
What iHeat publish for Sigenergy
iHeat have a brand page. The hero shows from £5,245. The 6kWh storage and inverter is £5,245 including VAT, monthly from £109. Ten-year warranty. LiFePO4. In stock on the morning we checked. Pair the same unit with All Black 450W panels and they list £7,845, monthly from £163.
| What iHeat publish | From (inc VAT) | Monthly from |
|---|---|---|
| 6kWh storage and inverter | £5,245 | £109 |
| All Black 450W panels plus 6kWh unit | £7,845 | £163 |
| Other floor: Hanchu 5kWh | £3,645 | £76 |
| Other floor: Powerwall 3 13.5kWh | £7,945 | £166 |
Source: iheat.co.uk/sigenergy and iheat.co.uk/battery-storage, 20 August 2026 morning. Hanchu and the Powerwall 3 are their other listed models, not this 6kWh unit.
iHeat show Which? Trusted Trader, MCS, and an Octopus Trusted Partner badge. The badge is not our quote path. Solar finance on iHeat is 9.9% APR Representative (Fixed). We are not calling their battery finance 0%. Their battery page also shows night about 13.16p and day about 26.11p. That is a tariff comparison on their page, not an installer button.
The unit can work without panels. Charge overnight, use the stored units in the day. That path is home battery without solar. If you want panels fitted with the box, use solar battery storage.
Heatable as the second quote
Heatable install SigEnergy. Their FAQ lists Tesla Powerwall 3, SigEnergy and Alpha ESS. They are a Tesla Premium installer. A shop tile on the same page still says “Powerwall 2”. That is an old label. They sell the Powerwall 3, not a Powerwall 2 as the current unit.
They list SigEnergy. There is no public cash from-price. We are not inventing one. The quote tool is the number. 0% APR available on batteries. Typical install about one day. 10-year battery warranty minimum. MCS. Which? Trusted Trader.
“Pay nothing ’til 2027” on their battery page is 0% VAT to 31 March 2027. That is tax, not 0% finance and not a grant.
VAT and what is not a grant
0% VAT on qualifying solar and battery supply-and-install runs to 31 March 2027, then 5%. Tax, not a grant. There is no BUS on a battery. Heat-pump grant rules are on the Boiler Upgrade Scheme page. This job is not that grant.
Warm Homes: Local Grant can include solar for qualifying England households. This page is a named 6kWh unit, not the grants guide. If you are hunting a grant rather than this hardware, start with solar panel grants.
iHeat first for the published 6kWh figure. Heatable second because they install SigEnergy.
iHeat list £5,245 or from £109 a month. Heatable list SigEnergy and do not publish a cash price. No BUS. 0% VAT on qualifying supply-and-install until 31 March 2027 is tax.
- 6kWh storage and inverter on their price list
- With panels from £7,845 / £163
- 10-year warranty, LiFePO4, in stock
- Which? Trusted Trader, MCS
- They list SigEnergy, Powerwall 3 and Alpha ESS
- 0% APR available on batteries
- Quote tool, about one day on site
- MCS, Which? Trusted Trader
- Want the public £5,245: start with iHeat. The 6kWh storage and inverter is on their list.
- Want a second MCS number who installs SigEnergy: add Heatable. Expect a quote, not a cash row.
- Want Tesla instead: the Tesla 13.5kWh page.
- Want Fox instead: Fox on iHeat, with no public from-price when we last checked.
- Want a wider who-to-quote list: who to quote for a solar battery.
Pick iHeat when
- You want the published £5,245 / £109 figures
- You want a named 6kWh storage and inverter row
- You want a monthly floor on the page
- You may add their 450W panel pair
Pick Heatable when
- You want a second MCS installer who lists SigEnergy
- You want 0% APR on the battery
- You do not need a public cash price today
- You may add Tesla or Alpha ESS on the same quote
Frequently asked questions about the 6kWh unit
iHeat list the storage and inverter at £5,245 inc VAT, or from £109 a month, on 20 August 2026 morning. With All Black 450W panels they list £7,845 / £163. Heatable do not publish a cash price.
Yes. Their FAQ names Tesla Powerwall 3, SigEnergy and Alpha ESS. There is no public from-price. Ask the quote. A shop tile still says Powerwall 2; they install the Powerwall 3 as the current Tesla unit.
Because they actually install SigEnergy, and they publish 0% APR on batteries. iHeat give you the public floor. A second MCS number is still worth having.
No BUS on a battery. 0% VAT on qualifying supply-and-install to 31 March 2027 is tax, not a grant. Warm Homes: Local Grant can include solar for some England households. That is not this 6kWh job.
We are not calling it 0%. They show a monthly from-figure. Their published solar rate is 9.9% APR Representative (Fixed). Heatable do publish 0% APR on batteries. Credit is subject to status. HomeBoiler is not a broker.
Yes. iHeat list the 6kWh storage and inverter on its own row, not as a panel kit. Charge overnight, use it in the day. Night-rate detail: home battery without solar.
This guide was last updated on 20 August 2026. iHeat figures are the public price list that morning. Heatable have no public cash price for SigEnergy. We are not a credit broker, lender or installer. Quotes and finance sit with iHeat and Heatable.