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Octopus Energy Heat Pump Tariff Review 2026

Octopus Energy has become the energy supplier of choice for heat pump owners in the UK. With multiple tariff options designed specifically for high-electricity households, they consistently offer some of the cheapest rates available. But which Octopus tariff is actually best for your heat pump, and how much can you realistically save?

We have analysed every Octopus tariff that benefits heat pump owners, calculated real-world savings, and spoken to homeowners using them. Here is our comprehensive review for 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.

How it works:

  • Off-peak windows (approximately 10p/kWh): 4am-7am, 1pm-4pm, 10pm-midnight
  • Peak window (approximately 30-35p/kWh): 4pm-7pm
  • Standard rate (approximately 22-24p/kWh): All other times
  • 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 nine 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

Originally designed for electric vehicle owners, Intelligent Go has become increasingly popular with heat pump households too. It provides a flat cheap rate overnight.

How it works:

  • Off-peak rate (approximately 7-10p/kWh): 11:30pm to 5:30am
  • Peak rate (approximately 27-30p/kWh): All other times

The overnight rate is lower than Cosy's off-peak windows, but you only get six hours of cheap electricity instead of nine. This tariff 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.

Eligibility: Smart meter required. Officially aimed at EV owners but available to non-EV households in many areas.

Agile Octopus

Agile is for the technically minded. It provides half-hourly pricing that changes throughout the day based on wholesale electricity costs.

How it works:

  • Prices update every 30 minutes and are published the day before
  • Overnight rates regularly drop to 5-8p/kWh
  • Peak rates can spike to 35-50p/kWh
  • Prices occasionally go negative (you get paid to use electricity)

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

Eligibility: Smart meter required. Open to all households.

Octopus Tracker

Tracker follows the wholesale electricity price with a day's notice. It is less volatile than Agile but still fluctuates daily.

  • Single unit rate that changes daily
  • Generally tracks below the Ofgem price cap
  • No off-peak windows — same rate all day

Tracker is not ideal for heat pump owners because it offers no off-peak advantage. You cannot save money by shifting usage to cheaper times. It can work out cheaper than a standard tariff overall, but Cosy or Intelligent Go will almost always beat it for heat pump households.

Real-World Savings: Cosy Octopus vs Standard Tariff

Let us calculate actual savings for a typical UK heat pump household using 4,500 kWh per year for heating.

Scenario: 3-Bedroom Semi-Detached, Air Source Heat Pump

On a standard flat tariff at 24.5p/kWh:

  • Annual heat pump electricity cost: £1,102.50

On Cosy Octopus (assuming 60% usage shifted to off-peak windows):

  • Off-peak usage: 2,700 kWh × 10p = £270
  • Standard rate usage: 1,350 kWh × 23p = £310.50
  • Peak usage: 450 kWh × 32p = £144
  • Annual heat pump electricity cost: £724.50
  • Annual saving: £378

That saving of nearly £380 is achieved with a realistic 60% shift to off-peak windows. Homeowners with good insulation and thermal mass report shifting 70-80% of usage, pushing savings above £450 per year.

Over the typical 15-20 year lifespan of a heat pump, those savings add up to £5,600 to £9,000. 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. Most heat pumps can be programmed with multiple time periods. Set yours to:

  • 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. Good insulation is not just about reducing heat demand — it is about giving you the flexibility to avoid paying peak rates. Even modest improvements like loft insulation top-up or draught-proofing can make a meaningful difference.

Get a Larger Hot Water Cylinder

A 200-300 litre hot water cylinder acts as a thermal battery. Heat it to 50-55°C during cheap windows and draw from it throughout the day. This avoids running the heat pump for hot water during expensive periods.

Use the Octopus App

Octopus's app shows you real-time pricing and your half-hourly usage. Review it weekly to identify where you are accidentally using expensive electricity and adjust your schedule accordingly.

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:

Choose Cosy if:

  • Your home's insulation is average (cavity walls, double glazing but not exceptional)
  • You want multiple off-peak windows to spread heating across the day
  • Your heat pump setup does not include a very large hot water cylinder
  • You prefer lower risk — Cosy's standard rate is reasonable even if you miss off-peak windows

Choose Intelligent Go if:

  • Your home is very well insulated and retains heat for 6+ hours easily
  • You have a large hot water cylinder (250+ litres) that can be heated overnight
  • You can genuinely do most heating overnight and need minimal daytime top-up
  • You also have an EV (double benefit from the cheap overnight rate)

For most heat pump owners, Cosy is the safer and more flexible choice. Intelligent Go can deliver slightly larger savings in the right circumstances, 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 (30-35p/kWh) 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. Set-and-forget does not maximise savings
  • Rates change: Octopus adjusts their tariff rates periodically. The rates quoted here are indicative for early 2026 — they may shift 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 other reasons (cooking, tumble dryer), 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 (typically gives you £50 credit)
  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 — typically takes 2-3 weeks
  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 in particular strikes the right balance between low off-peak rates and manageable peak rates, with enough cheap windows to suit most households. The potential savings of £350-450 per year make switching a no-brainer if you are currently on a standard tariff.

The only reason not to choose Octopus would be if another supplier offers a significantly better deal for your specific circumstances — which, in our experience, is uncommon. Check our full tariff comparison to see how other suppliers stack up.

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 Intelligent Go, Agile, or their standard Flexible tariff. 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 Intelligent Go or Agile instead, which are open to all customers with a smart meter.

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.