If you’re a UK homeowner bracing for another winter of unpredictable energy bills, you’re not alone. Gas prices remain volatile, and with the government’s push towards net zero, air source heat pumps are firmly in the spotlight.
Enter Mitsubishi’s Ecodan range - a trusted, Japanese-engineered system that’s been quietly (literally) warming British homes since 2007.
Designed for our damp, chilly climate, the Ecodan promises reliable performance and whisper-quiet operation.
But is it really worth the investment for your semi-detached or terraced home?
In this review, we’ll skip the marketing jargon and dive into the real-world data - covering efficiency, running costs, and honest pros and cons.
Spoiler: it’s one of the most balanced, dependable heat pumps on the UK market.
Meet the Mitsubishi Ecodan
The Mitsubishi Ecodan isn’t one single heat pump - it’s a full family of air source systems built specifically for UK homes, from cosy city flats to spacious detached houses.
Standout models include the PUZ-WZ, a compact monobloc ideal for smaller properties, and the PUZ-HW, a higher-capacity unit designed for larger homes with hot water cylinders.
At its core is inverter technology, which automatically adjusts output (like a dimmer switch) to match your home’s heating needs - cutting energy waste and improving efficiency.
Engineered for British winters, the Ecodan keeps running smoothly down to -25°C, while its Quiet Mode reduces fan speed for whisper-level operation - a genuine neighbour-pleaser.
In simple terms? It draws heat from the outside air - even when it’s freezing - and uses it to warm your radiators or underfloor system.
And there’s a green bonus too: the latest R32 and R290 refrigerants slash global-warming potential compared to older systems, making the Ecodan one of the most eco-friendly options on the market.
How Quiet Are Mitsubishi Heat Pumps, Really?
No one wants a heat pump that sounds like a leaf blower at a garden party. Thankfully, the Mitsubishi Ecodan is one of the quietest systems on the UK market.
The Ultra Quiet PUZ-WZ model operates at just 45–48 dB - roughly the same as a gentle fridge hum or a quiet chat in the kitchen.
That’s noticeably quieter than rivals like the Daikin Altherma 3 (~50 dB) and Samsung EHS (~52 dB). In many cases, that low output means it can skip planning permission altogether.
Smart placement helps even more:
Position it against a garden wall or behind a fence for natural sound shielding.
Use anti-vibration mounts to eliminate low-frequency rumbles.
And because the monobloc design houses everything in a single outdoor unit (no noisy indoor splits), it’s especially well-suited for terraces, semis, and flats where outdoor space - and neighbourly goodwill - are at a premium.
Installation & Space Requirements
Installing a Mitsubishi Ecodan is generally straightforward - especially in the hands of an MCS-certified installer - but space planning is key to a smooth setup.
The outdoor unit is impressively compact, measuring roughly 1.0m (W) x 0.6m (D) x 0.8m (H) for the 5–8.5 kW models.
That’s small enough to tuck neatly into most gardens, patios, or side alleys without dominating the space.
Indoors, you’ll need space for a hot-water cylinder (150–200 L) and, in some cases, a buffer tank to help stabilise water flow particularly in older radiator systems.
For most semi-detached and terraced homes, the monobloc design is a dream: no refrigerant pipes running indoors, just water and electrical connections.
Living in a flat or property with limited outdoor access? The Ecodan R32 Compact is specifically designed for tighter spaces, offering flexible installation with minimal fuss.
Installer feedback highlights a few practical tips worth knowing:
Leave at least 10 cm of clearance around the outdoor unit for airflow.
Flush the heating system with a cleaner like Fernox F3 before connecting to avoid debris build-up.
Expect installation to take 1–2 days, or slightly longer if you’re opting for a hybrid setup (Ecodan + existing boiler) for added resilience.
💡 Not sure if your home’s suitable?
Get a Heat Pump Quote with Heatable - we’ll match you with trusted local installers who can assess your space and recommend the right setup.
Cost & Grants
Let’s be honest - the upfront cost of a heat pump can sting. But with grants like the Boiler Upgrade Scheme (BUS), things start looking a lot brighter.
A full Mitsubishi Ecodan installation - including the unit, hot-water cylinder, and labour - typically lands between £7,000 and £12,000 before incentives. That’s competitive for a premium system.
Apply the £7,500 BUS grant, and your out-of-pocket cost drops to as little as £0–£4,500. Not bad for a low-carbon upgrade that could cut your heating bills for decades.
The BUS is available to homeowners in England and Wales replacing fossil fuel systems - and as of 2025, there are no insulation requirements to qualify. (Scotland and Northern Ireland have their own funding pots, so check local options.)
Running costs are already covered above - but remember, they can fall even further with smart tariffs like Octopus Cosy.
As for peace of mind: the Ecodan comes with a 3-year standard warranty, extendable to 7 years when registered by an accredited installer.
At a Glance: Mitsubishi vs Rivals:
Feature | Mitsubishi Ecodan | Daikin Altherma 3 | Vaillant aroTHERM Plus |
Full install (pre-grant) | £7,000–£12,000 | £8,000–£13,000 | £7,500–£12,500 |
SCOP (avg) | 3.9–4.5 | 3.3–4.6 | 4.9–5.0 |
Noise (dB) | 45–48 | 50–52 | 45–50 |
Warranty | 3–7 years | 3–5 years | 2–7 years |
Best for | Quiet UK winters | Extreme cold (-28°C) | High-temp radiators |
(Data averaged from 2025 UK specs. See our Best Heat Pump UK 2025 guide for full comparisons.)
Pros and Cons
Every system has its strengths and quirks, and the Mitsubishi Ecodan is no exception.
Here’s an honest breakdown based on real UK installations, reviews, and performance data:
Pros:
Reliable, proven, and trusted brand. Over 15 years of UK installations and a 4.3 out of 5 Trustpilot rating.
Whisper-quiet operation. Just 45 to 48 decibels, quieter than most fridges and ideal for built-up areas.
Excellent cold-weather performance. Maintains strong efficiency even below freezing, tailor-made for British winters.
Hybrid-ready. Can easily integrate with existing boilers for flexible backup or gradual upgrades.
Eco-friendly refrigerants. Uses low-GWP R32 and R290 gases that align with future carbon regulations.
Low running costs. Particularly when paired with smart tariffs such as Octopus Cosy or Agile.
Cons:
Higher upfront cost. Premium engineering comes at a price, typically one to two thousand pounds more than entry-level systems from Samsung or Midea.
Needs good insulation. Performs best in well-sealed homes; older or draughty terraces may need extra preparation to maximise efficiency.
Servicing availability can vary. Mitsubishi’s UK network is expanding, but remote areas may face longer lead times unless covered by a service plan.
Indoor cylinder space required. Not a dealbreaker, but worth planning for if you’re switching from a combi boiler setup.
In short, the Ecodan is one of the most refined, reliable, and UK-ready heat pumps available.
Like any premium system, it performs best in well-prepared homes with professional installation.
For more on the trade-offs, see our Air Source Heat Pump Pros and Cons guide.
Next Steps For Your Heat Pump Journey:
When planning to install a heat pump for your home, there are several important factors to consider. Make sure to refer to the following guides to help you make informed decisions:
To dive deeper into these topics, head over to our advice section or check out our YouTube channel to learn more.
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