Octopus Energy Heat Pump Tariff Review 2026

Heat pump owners who shift most of their heating into cheap windows can save hundreds of pounds a year compared with a standard variable tariff. With three separate tariff products used by high-electricity households, Octopus has become the default choice for heat pump owners across the UK. But the tariffs are not interchangeable — the wrong Octopus product could leave savings on the table.

We have reviewed the Octopus tariffs that heat pump owners use and worked through an example savings calculation. Here is our review for 2026, covering Cosy Octopus, Intelligent Octopus Go (an EV tariff) and Agile. Rates are regional and change often, so check Octopus for current rates. Last reviewed October 2026.

Octopus Tariffs That Benefit Heat Pump Owners

Octopus does not offer just one heat pump tariff — they have several options, each suited to different situations. Understanding the differences is crucial to picking the right one.

Cosy Octopus

Cosy Octopus is the flagship heat pump tariff and the one most owners should start with. It provides multiple cheap windows throughout the day, specifically timed to align with when heat pump owners typically need to heat their homes.

• Cheap windows (51% below your regional day rate): 4am-7am, 1pm-4pm, 10pm-midnight
• Peak window (50% above your regional day rate): 4pm-7pm
• Day rate: All other times (rates are regional: check Octopus for your area)
• Standing charge: Standard daily standing charge applies

The genius of Cosy is the three off-peak windows. The early morning window lets you pre-heat the house before waking. The afternoon window gives you a mid-day boost. The late evening window is perfect for heating your hot water cylinder overnight. Together, they give you eight hours of cheap electricity per day.

Eligibility: You need a smart meter and a registered heat pump. Octopus will verify your heat pump installation — they usually accept MCS-certified installations or evidence of your heat pump system.

Intelligent Octopus Go

Intelligent Octopus Go is an electric vehicle tariff, not a heat pump tariff: it usually requires a compatible EV or home charger. If you have both an EV and a heat pump, you can use its cheaper overnight rate for heating and hot water too.

• Cheap rate: Overnight (check Octopus for current rates and hours)
• Other times: Standard day rate

You get a single overnight cheap period rather than Cosy's three windows. Using it for heating works best if you have a large hot water cylinder (ideally 250 litres or more) and excellent insulation that can hold heat through the day.

Agile Octopus

Agile is for the technically minded. It provides half-hourly pricing that changes throughout the day based on wholesale electricity costs. Overnight prices are often well below the price cap rate, while peak prices can be far higher. Prices occasionally go negative — meaning you get paid to use electricity during periods of high renewable generation.

Agile can deliver the lowest annual costs of any Octopus tariff if you are willing to actively manage consumption. However, it carries more risk — a cold snap with high wholesale prices could mean expensive days.

Worked Example: Cosy Octopus vs Standard Tariff

Here is a worked example for a UK heat pump household using 4,500 kWh of electricity per year for heating.

That saving of about £360 assumes 60% of use is shifted into the cheap windows. Homes with good insulation and thermal mass can shift more, which increases the saving; running the heat pump in the 4pm-7pm peak reduces it.

Over the typical 15-20 year lifespan of an air source heat pump, savings of that size would add up to roughly £5,400 to £7,200 if rates stayed the same. That is a significant chunk of the installation cost recovered through smarter energy purchasing alone.

How to Get the Most from Octopus Cosy

Optimise Your Heating Schedule

The key to maximising savings on Cosy is aligning your heat pump schedule with the cheap windows:

• 4am-7am: Run at full capacity to pre-heat the house and hot water
• 7am-1pm: Reduce to minimum or turn off (house coasts on stored heat)
• 1pm-4pm: Boost back up during the afternoon off-peak window
• 4pm-7pm: Reduce to minimum — this is the expensive peak period
• 7pm-10pm: Light top-up at standard rate if needed
• 10pm-midnight: Heat hot water cylinder during final off-peak window

Invest in Insulation

The better your home retains heat, the longer it coasts between off-peak windows. Even modest improvements like loft insulation top-up or draught-proofing can make a meaningful difference to how much you shift away from peak rates.

Consider Solar to Complement Your Tariff

If you pair Octopus Cosy with solar panels, you generate free daytime electricity that covers standard-rate hours, while the heat pump runs on cheap off-peak electricity in the Cosy windows.

Cosy Octopus vs Intelligent Go: Which Is Better for Heat Pumps?

This is the question most heat pump owners wrestle with. Here is our honest assessment:

For most heat pump owners, Cosy is the safer and more flexible choice. Intelligent Go is an EV tariff, so it is only an option if you have an eligible electric vehicle or charger, but Cosy's three daily off-peak windows give you much more room to manoeuvre.

Drawbacks of Octopus Heat Pump Tariffs

No tariff is perfect. Here are the honest downsides:

• Peak rates are high: Cosy's peak rate (50% above your regional day rate) is above a standard tariff. If you run your heat pump during peak hours, you pay more than you would on a flat rate
• Requires discipline: You need to actively manage your heating schedule to maximise savings
• Rates change: Octopus adjusts tariff rates periodically with wholesale price movements
• Whole-house tariff: The rates apply to all your electricity, not just the heat pump. If you use lots of electricity during peak hours for cooking or laundry, those costs increase too
• Smart meter essential: No smart meter, no access to time-of-use tariffs

How to Switch to Octopus

Switching to Octopus is straightforward:

1. Visit the Octopus Energy website or use a referral link (referral credit offers vary)
2. Enter your postcode and current energy usage
3. Choose your tariff — select Cosy Octopus if you have a heat pump
4. Provide your heat pump details when prompted (make, model, MCS certificate number)
5. Octopus handles the switch from your existing supplier
6. If you do not have a smart meter, Octopus will arrange installation

There are no exit fees with Octopus (they are a variable-rate supplier on most tariffs), and your supply will not be interrupted during the switch.

Our Verdict

Octopus Energy is the best energy supplier for heat pump owners in 2026. Cosy Octopus strikes the right balance between cheap windows and a short peak period, with enough cheap windows to suit most households. Savings of several hundred pounds a year are possible if you shift most of your use into the cheap windows (about £360 in our worked example), so it is worth checking against your current tariff. Rates change, so check Octopus for current rates in your area.

Check our full tariff comparison to see how other suppliers like EDF, Scottish Power, and British Gas stack up, and use our running costs guide to model your specific savings.

Frequently Asked Questions

Is Octopus Cosy available in my area?

Cosy Octopus is available across Great Britain (England, Scotland, and Wales) wherever Octopus supplies electricity. Enter your postcode on their website to confirm availability and see the exact rates for your region, as they vary slightly by area.

Can I switch between Octopus tariffs easily?

Yes, you can switch between Octopus tariffs without penalty. If you try Cosy and find it does not suit your lifestyle, you can move to Agile, their standard Flexible tariff, or Intelligent Octopus Go if you have an eligible EV. Changes typically take effect within a few days.

Does Octopus work with all heat pump brands?

The tariff works with any heat pump — Cosy Octopus does not integrate directly with your heat pump system. You simply schedule your heat pump's timer to align with the cheap windows. Some newer heat pump models from brands like Vaillant and Samsung have Octopus integration features, but they are not required.

What if my smart meter does not work properly?

If your smart meter loses connection or is not sending half-hourly data, Octopus may bill you on estimated usage at the standard rate until the issue is resolved. Contact them to arrange a meter check or replacement if this happens.

Can I use Cosy Octopus without a heat pump?

Cosy is specifically for heat pump owners and you need to provide evidence of your installation. If you do not have a heat pump, consider Agile (which needs a smart meter), or Intelligent Octopus Go if you have an eligible EV.

How do Octopus rates compare to the Ofgem price cap?

Octopus's standard rate on Cosy is generally at or slightly below the Ofgem price cap. The off-peak rates are significantly below the cap. The peak rate exceeds the cap, but since it only applies for three hours per day, most customers pay less overall than they would on a capped flat-rate tariff.