LG Therma V vs Daikin Altherma

Which Is Better: LG Therma V or Daikin Altherma?

Neither is universally better; the choice depends on whether you prefer LG’s R290 positioning or Daikin’s Altherma platform. According to LG’s THERMA V R290 information, the unit can deliver leaving water temperatures up to 75°C and operate down to -28°C ambient, while Daikin UK’s Altherma 3 catalogue (2025) gives leaving water temperatures up to 65°C and A+++ efficiency positioning. See also: BUS Grant 2026 guide.

For you, that means the decision is less about a simple winner and more about which system logic fits your retrofit, your installer, and your appetite for refrigerant and controls differences. Read our complete guide to heat pumps in the UK, best heat pump brands guide, and heat pump running costs guide. If your project is eligible, our BUS grant survey page is the route for air source heat pump applications, subject to eligibility.

What Are the Main Technical Differences?

The main technical differences are refrigerant, high-temperature capability, control ecosystem, and retrofit framing. According to LG’s THERMA V R290 product information, LG pushes 75°C leaving water temperature with operation down to -28°C, while Daikin UK’s Altherma 3 material (2025) presents an R32 system with up to 65°C leaving water temperature and a COP up to 5.1 at 7°C/35°C.

Prices and services correct at time of writing — always request a current quote.

The important point is that these figures come from different manufacturer contexts, so they are not a one-line verdict. What they do show is that LG leans harder into R290 and extreme-condition messaging, while Daikin leans into platform maturity, controls, and established installer familiarity.

Which One Usually Fits Retrofit Better?

In retrofit, LG often suits homeowners who want R290 and a stronger high-temperature story, while Daikin often suits projects that value an established UK platform and familiar controls. According to Energy Saving Trust (2026), heat pump performance still depends on low flow temperatures and suitable system design, so neither brand removes the need for proper emitter review and heat-loss calculations.

LG can be appealing if your home needs a reassuring temperature story and your installer is comfortable with the platform. Daikin can be appealing if you want an established route with broad UK market presence, strong controls familiarity, and a track record many installers already understand well.

Typical retrofit decision points include:

1. whether your property actually needs a stronger high-temperature message
2. how much value you place on R290 versus R32
3. which installer is stronger on commissioning and controls
4. whether the quoted design is genuinely low-temperature and efficient

If you are also planning solar, battery storage, or an all-electric home, that wider package can matter more than the badge alone. Our solar battery storage guide and heat pump cost article are useful next reads.

What Do Homeowners Most Often Get Wrong?

The most common mistake is assuming high quoted temperature means you can ignore radiator design and still get efficient running. According to MCS (2025), installation quality, system design, and commissioning remain central to heat pump performance, so a high brochure figure does not replace good engineering.

Another common error is reading cold-weather claims as if they guarantee comfort on their own. A unit can have an impressive published low-ambient figure and still underperform in practice if the emitters, controls, or hot-water setup are weak. The outdoor unit is only one part of the delivered result.

Typical comparison mistakes include:

• treating refrigerant as the only meaningful difference
• assuming any high-temperature unit will work with any existing radiator system
• choosing on brochure claims before the survey is complete
• overlooking installer competence and aftercare

That is why the smarter question is not which brand sounds strongest online, but which quoted system makes the most sense in your house.

What Does This Mean in London, Surrey, and TW Homes?

In London, Surrey, and TW homes, the better fit between LG Therma V and Daikin Altherma usually depends more on the property and installer than on the headline spec sheet. According to Ofgem (April 2026), electricity remains priced at 24.5p/kWh, so poor controls or unnecessarily high flow temperatures can push up running costs regardless of brand.

Across Victorian terraces, 1930s semis, and detached South East homes, the key question is whether the quoted system is proportionate. LG may suit some homeowners who want R290 and stronger temperature reassurance. Daikin may suit others who prefer a more familiar, mature UK market route and a platform many installers already know well.

The local lesson is that your survey should settle the answer. In this region, radiator capacity, cylinder space, outdoor-unit location, and acoustic context usually matter more than online debate. See our heat pump installation process guide and heat pump size calculator article for the practical next layer.

It is also worth comparing who will maintain and optimise the controls after handover. In real homes, that support can affect comfort and seasonal efficiency more than a small brochure difference in top-line performance.

If your project is also moving towards solar generation or battery storage, the better brand choice may be the one that integrates more cleanly into the wider electrical strategy rather than the one with the strongest isolated headline.

How Electromatic Can Help

If you are comparing LG Therma V vs Daikin Altherma, the next step is a survey that checks heat loss, emitters, hot water, and controls together before the brand is locked in. According to MCS (2025), compliant system performance depends on design quality and commissioning rather than on brochure specifications alone.

Electromatic can explain where each route makes more sense in practical retrofit terms and whether the wider project should include solar or battery planning at the same time. We work under MCS certification via our accredited umbrella partner, and where the installation is eligible we can handle BUS grant applications for air source heat pumps, subject to eligibility. Our typical lead time is 2-4 weeks, and we can coordinate ASHP and solar work through one contractor.

Book your free home survey →

Call us: 07718 059 284 | Email: admin@electromatic.uk

Frequently Asked Questions

How much does refrigerant choice matter between LG and Daikin?

It matters, but not as much as overall system design. Many homeowners like R290 for its lower GWP, whilst others are happy with a mature R32 platform if the design, controls, and installer confidence are stronger.

Can I get the BUS grant (subject to eligibility) with LG or Daikin?

Yes, both brands can be used in eligible domestic ASHP projects. The BUS grant is £7,500 subject to eligibility, and the system still needs to meet design and scheme requirements.

Do I need new radiators with either brand?

Possibly. The answer depends on your heat-loss figures and existing emitter capacity, not just on whether the brand publishes a high maximum water temperature.

Is Daikin easier to service than LG?

That depends more on your installer and local support network than on the badge alone. In practice, the best service outcome comes from a properly documented install with clear handover and aftercare.

Which brand is more suitable for a Surrey or London retrofit?

Either can work well if the design is right. Usually the better option is the one your installer can justify clearly for your property, radiator setup, hot-water demand, and control preferences.

The information in this article is for general guidance only and does not constitute financial, legal, or technical advice. Energy savings estimates are based on typical UK household data from the Energy Saving Trust and Ofgem (April 2026 price cap). Actual savings depend on your property type, insulation levels, energy usage patterns, and electricity tariff. The Boiler Upgrade Scheme (BUS) grant of £7,500 is subject to eligibility criteria set by Ofgem — not all properties qualify. Electromatic M&E Ltd operates under MCS certification via an accredited umbrella partner. All installations comply with Building Regulations Part L and MCS standards. E&OE.

Written by Electromatic M&E Ltd — ASHP & Solar installer, London & Surrey (electromatic.uk)

Last updated: April 2026 | Electromatic M&E Ltd, Company No. 13837345