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Comparison · 3 picks
Aira vs BOXT vs Octopus Heat Pump UK 2026 (3-Way)
UK heat-pump installs have consolidated around three high-volume routes: Aira, BOXT, and Octopus Energy. They've taken radically different commercial routes - one subscription, two purchase - and the right answer depends entirely on what trade-off you're willing to make. This guide walks through where each pulls ahead.
The commercial models in one line each
What you actually pay - and how.
Aira: 15-year subscription. You pay a monthly fee (typically GBP 70-120/mo depending on system size) and Aira owns + maintains the heat pump. Includes equipment + install + ongoing service + electricity-cost guarantee. No upfront cost or BUS grant interaction (Aira keeps the grant as part of the subscription pricing).
BOXT: Fixed-price purchase install. Photo-based quotes, post-BUS-grant price shown upfront (typically GBP 3,500-7,000 net of grant for standard properties). You own the heat pump outright. 7-year warranty.
Octopus Cosy 6: Survey-based purchase install with Cosy Octopus tariff integration. Survey + design + install, typically GBP 4,500-8,000 net of grant. You own the heat pump. 10-year warranty on the unit. The Cosy Octopus electricity tariff has preferential rates for Cosy 6 owners.
At a glance
All 3 options side by side.
 Aira |  BOXT |  Octopus Cosy 6 | |
|---|---|---|---|
| Best for | - | - | - |
| Commercial model | 15-year subscription | Fixed-price purchase | Survey-based purchase |
| Upfront cost | GBP 0 | GBP 3,500-7,000 post-grant | GBP 4,500-8,000 post-grant |
| Monthly cost | ~GBP 70-120/mo | GBP 0 (or finance) | GBP 0 (or Cosy Octopus tariff) |
| BUS grant | Kept by Aira (built into pricing) | Passed to customer (price shown post-grant) | Passed to customer (post-survey quote) |
| Ownership | Aira owns - you subscribe | Customer-owned outright | Customer-owned outright |
| Equipment | Aira Indoor + Outdoor units (Daikin-derived) | Vaillant aroTHERM plus + Daikin | Cosy 6 (R290, in-house design) |
| Warranty | Full coverage during 15-yr term | 7 years | 10 years on unit |
| Install timeline | 6-8 weeks | 4-6 weeks | 8-12 weeks |
| Check price | Check price | Check price |
The picks in detail
Aira Aira
Pros
- Zero upfront cost - subscription model removes capital barrier entirely
- All maintenance + repairs included during 15-year subscription
- Electricity-cost guarantee as part of subscription pricing
- Aira's in-house Indoor + Outdoor units engineered together
Cons
- Total cost over 10-15 years significantly higher than BOXT/Octopus purchase routes
- No ownership of the heat pump - effectively a long-term lease
- Locked into Aira for the subscription term (15 years)
- BUS grant goes to Aira (built into pricing) - customer doesn't see direct grant benefit
BOXT (× Vaillant) BOXT
Pros
- Fastest install timeline of the three (4-6 weeks)
- Fixed-price photo-based quote - no survey commitment before pricing
- Customer-owned heat pump with 7-year warranty
- Established Vaillant aroTHERM plus equipment with long UK track record
Cons
- Photo-based quotes occasionally miss edge cases that catch you later
- 7-year warranty is shorter than Octopus's 10
- No supplier-tariff integration vs Octopus's Cosy Octopus advantage
- Less suited to complex/period properties than survey-based routes
Octopus Energy Octopus Cosy 6
Pros
- Survey-based engineering catches issues photo quotes miss
- Cosy 6 uses R290 refrigerant (low GWP, designed for UK conditions)
- 10-year warranty on the heat pump unit
- Cosy Octopus tariff bundling delivers best UK run-cost economics
Cons
- Longest install timeline (8-12 weeks)
- Survey commitment required before quote is known
- Locked to Octopus Energy as supplier for the Cosy Octopus tariff benefit
- Slightly higher upfront price vs BOXT for equivalent sizing
When Aira wins
When monthly cashflow matters more than long-term ownership economics.
Aira's subscription model is right for:
- Buyers without the upfront capital for a GBP 4-8k install. The subscription removes that hurdle entirely.
- Renters with landlord consent who want a heat pump but can't justify a permanent capital install (Aira's removal/replacement logic at end-of-term is simpler than buyer-owned).
- Buyers who prefer 'fix it for me' service over the 'own it + arrange repairs' model. Aira handles all maintenance + repairs during the 15-year term.
- Risk-averse first-time heat-pump buyers who want the electricity-cost guarantee Aira offers as part of the subscription.
Trade-off: total cost over 15 years (GBP 12,600-21,600 in subscription fees) is significantly higher than buying outright (GBP 4-8k + ~GBP 1-2k cumulative servicing). Aira is the right choice if cashflow matters more than long-term value.
When BOXT wins
When you want predictable fixed-price install and fastest timeline.
BOXT is the right pick for:
- Standard properties (3-4 bed detached/semi, conventional wet-radiator heating, replacing gas combi) where a photo-based quote is sufficient.
- Buyers who value price certainty upfront over survey-based engineering rigour.
- End-of-life boiler scenarios where you need a fast timeline (4-6 weeks vs 8-12 for Octopus or 6-8 for Aira).
- Buyers happy with Vaillant aroTHERM plus as the heat-pump unit (long UK track record, reliable parts supply).
Trade-off: 7-year warranty (vs Octopus's 10), no tariff integration (vs Octopus + Aira), occasional friction from the photo-quote model on edge-case properties.
When Octopus Cosy 6 wins
When engineering rigour + run-cost economics matter most.
Octopus is the right pick for:
- Complex properties (period homes, extensions, mixed insulation, awkward heating loads) where survey-based design catches issues.
- Cosy Octopus tariff users - the bundled heat-pump tariff has the most attractive UK run-cost economics when paired with the Cosy 6.
- Buyers wanting low-GWP refrigerant - the Cosy 6 uses R290 (GWP 3) by default.
- 10-year warranty preference - 3 years longer than BOXT.
- Long-term Octopus Energy customers who'll benefit from the supplier-integrated service experience.
Trade-off: longer timeline (8-12 weeks), survey commitment before price is known, locked to Octopus as supplier for the Cosy tariff benefit.
Total cost over 10 years
Subscription vs purchase economics on a realistic timeline.
For a typical 3-bed semi-detached property over 10 years (including run cost at off-peak EV-style tariff):
- Aira: GBP 0 upfront + ~GBP 11,400 in subscription fees (10 × 12 × GBP 95/mo) + ~GBP 4,000 in electricity (Aira includes electricity-cost guarantee). Total: ~GBP 15,400.
- BOXT: ~GBP 5,000 upfront install + ~GBP 4,500 in electricity (no preferential tariff) + ~GBP 600 in cumulative servicing. Total: ~GBP 10,100.
- Octopus Cosy 6 (with Cosy Octopus tariff): ~GBP 6,000 upfront install + ~GBP 3,500 in electricity (cheaper via tariff) + ~GBP 500 in cumulative servicing. Total: ~GBP 10,000.
BOXT + Octopus are roughly equivalent over 10 years; Aira is ~GBP 5k more expensive but removes the upfront capital + bundles in maintenance.
Bottom line
Three different right answers for three different buyer profiles.
The three routes target genuinely different buyer profiles:
- Aira for buyers without upfront capital, renters, or anyone preferring service-led 'fix it for me' over capital ownership. Pay more total; pay nothing upfront.
- BOXT for standard properties wanting the fastest, most predictable fixed-price purchase install. The default choice for the modal UK buyer.
- Octopus Cosy 6 for complex properties wanting engineering-led design + the best run-cost economics via the Cosy Octopus tariff integration.
All three handle BUS grant + warranty + ongoing service. Pick by the trade-off axis that matters most for your situation.