Vaillant aroTHERM plus Review: Prices & Grants for Irish Homes
Vaillant is one of Germany's oldest heating manufacturers, and its aroTHERM plus air to water heat pump has a reputation as one of the quietest units you can put beside an Irish house. It ranks #7 on our best heat pumps in Ireland list. Here's our independent review: the specs that matter, typical installed prices, SEAI grant eligibility, the truth about Irish availability, and how it compares to Viessmann, its closest German rival.
Quick Answer
The Vaillant aroTHERM plus is a premium German air to water heat pump with a SCOP of around 4.7, R-290 propane refrigerant, and flow temperatures up to 75°C, high enough that many Irish retrofits keep their existing radiators. It is among the quietest air-source units on the market at its low setting, which makes it a strong pick for urban and semi-detached homes. Expect €12,000–€15,500 installed before the SEAI grant of up to €12,500. It is on the SEAI HARP list, so the grant applies in full. The trade-off: Vaillant has no Irish office, so supply and aftercare run through UK-based support and independent distributors.
Who Are Vaillant?
Vaillant was founded in 1874 in Remscheid, Germany, and is one of Europe's biggest heating manufacturers. Irish homeowners are most likely to know the name from gas boilers; the aroTHERM plus is its flagship air to water heat pump and the model that has won it a following among heat pump installers across Britain and Europe.
Two things define the aroTHERM plus. First, noise (or the lack of it). At its low setting it is among the quietest air-source units sold here: Vaillant publishes sound power from the high-20s to mid-40s dB(A) depending on output, and several output sizes carry Quiet Mark accreditation. That makes it the unit we'd shortlist first for terraced, semi-detached, and urban homes where the outdoor unit sits close to a bedroom window or a neighbour's boundary. Second, flow temperature: up to 75°C, joint-highest on our list (matched by the Nibe S2125 and Mitsubishi's Ecodan R290), which means many retrofits avoid a radiator swap entirely.
The catch is the supply chain. Vaillant has no Irish office, so units reach Ireland through independent distributors and merchants, with manufacturer support running from the UK operation. The hardware is excellent; the local installer pool is smaller than Daikin's or Mitsubishi's, and aftercare depends more on your installer than on a manufacturer-run Irish service network. That's why it sits at #7 on our ranking rather than higher.
1874
Founded (Germany)
4.7
SCOP (aroTHERM plus)
75°C
Max flow temperature
R-290
Natural refrigerant
Vaillant aroTHERM plus Specifications
The aroTHERM plus is an air to water monobloc: all the refrigerant circuit lives in the outdoor unit, so no F-gas engineer is needed indoors. Vaillant lists it in 3.5, 5, 7, 10, and 12 kW output sizes, which covers everything from a small well-insulated home up to a large detached retrofit. It pairs with Vaillant's uniTOWER indoor unit or a separate hot water cylinder, depending on the layout your installer proposes.
| Specification | aroTHERM plus |
|---|---|
| Type | Air to water, monobloc |
| Output sizes | 3.5, 5, 7, 10, 12 kW |
| SCOP | ~4.7 |
| Max flow temperature | 75°C |
| Refrigerant | R-290 (propane, ultra-low GWP) |
| Sound power | High-20s to mid-40s dB(A) at low setting, depending on output |
| Operating range | Down to around -25°C |
| SEAI HARP list | Yes, grant eligible |
| Warranty | 5 years (7 with Advance pack) |
Source: Vaillant aroTHERM plus product documentation. Confirm the exact output size, model code, and warranty terms on your quote. The 7-year warranty depends on your installer's accreditation with Vaillant and registration of the system.
Why the quiet running matters
Planning guidance and common sense both care about outdoor unit noise, and it's the number one complaint from neighbours of badly sited heat pumps. At its low-noise setting the aroTHERM plus publishes sound power figures from the high-20s dB(A), quieter than a whisper, which gives installers far more siting freedom on terraced and semi-detached plots where the unit ends up near a window or boundary wall.
Why the 75°C flow temperature matters
Most heat pumps run radiators at 35–55°C, which is why retrofits often need bigger radiators. The R-290 refrigerant lets the aroTHERM plus push up to 75°C on cold days (boiler territory), so more retrofits keep their existing radiators, cutting thousands off the installation cost.
Vaillant aroTHERM plus Cost in Ireland
Expect €12,000–€15,500 fully installed for an aroTHERM plus system before the grant, depending on house size, cylinder work, and whether any radiators change. As a rough guide to typical quotes (every house is different, so treat these as ballparks, not prices):
| Home type | Typical size | Typical installed quote (before grant) |
|---|---|---|
| Small / well-insulated home | 3.5–5 kW | €12,000–€13,000 |
| Typical 3-bed semi | 5–7 kW | €12,500–€14,000 |
| Large / detached retrofit | 10–12 kW | €14,000–€15,500 |
The aroTHERM plus is on the SEAI HARP list, so the full SEAI grant of up to €12,500 (from 3 February 2026) applies: €6,500 for the heat pump itself, €2,000 towards heating system upgrades, and a €4,000 renewable heat bonus. Your home must have been built before 2021 and the system fitted by an SEAI-registered installer. Retrofits that keep their existing radiators (which the 75°C flow temperature makes far more likely) land at the lower end of the ranges above. For the full line-by-line breakdown of what you'd pay, see our heat pump installation cost guide, or check the SEAI grants guide for eligibility.
Vaillant aroTHERM plus vs Viessmann Vitocal 150-A: Which Is Better for Ireland?
These are the two German R-290 rivals on our list, and on paper they are closer than any other pairing. Viessmann edges efficiency; Vaillant edges noise, flow temperature, and warranty:
| Feature | Vaillant aroTHERM plus | Viessmann Vitocal 150-A |
|---|---|---|
| SCOP | ~4.7 | Up to 4.9 |
| Max flow temperature | 75°C | 70°C |
| Refrigerant | R-290 | R-290 |
| Noise | Among the quietest at low setting (high-20s dB(A) sound power) | Quiet, but not class-leading |
| Installed cost | €12,000–€15,500 | €12,000–€16,000 |
| SEAI grant | Up to €12,500 | Up to €12,500 |
| Irish network | Small; no Irish office, UK-supported | Small but growing distributor network |
| Warranty | 5 years (7 with Advance pack) | Up to 5 years (installer-dependent) |
Verdict: the Vitocal 150-A takes the efficiency crown; the aroTHERM plus wins on quietness, the joint-highest flow temperature on our list (matched by the Nibe S2125 and Mitsubishi's Ecodan R290), and a cleaner warranty path. For urban and semi-detached siting where the outdoor unit sits near a boundary, we'd lean Vaillant. In practice the deciding factor for both is the same: which brand has a genuinely experienced installer near you. Get both quoted if you can.
Vaillant Heat Pumps: Frequently Asked Questions
Are Vaillant heat pumps available in Ireland?
Yes, despite what you may read in Facebook groups. Vaillant has no Irish office, which is where the 'not available on the Irish market' confusion comes from: there's no Irish sales operation, so units reach Ireland through independent distributors and merchants, with manufacturer support running from the UK. The aroTHERM plus is on the SEAI HARP list, so it's fully grant eligible here. The practical implication is that the pool of Irish installers who fit Vaillant regularly is small. Confirm your installer's Vaillant experience and how warranty support would be handled before signing.
How much does a Vaillant aroTHERM plus cost in Ireland?
Typical quotes run €12,000–€15,500 fully installed before the grant, depending on output size, cylinder work, and whether any radiators change. After the SEAI grant of up to €12,500, the net cost for qualifying homes falls substantially. Retrofits that keep their existing radiators (likelier with the 75°C flow temperature) land at the lower end.
Is the aroTHERM plus eligible for the SEAI grant?
Yes. The Vaillant aroTHERM plus is on the SEAI HARP (Home-heating Appliance Register of Performance) list. The grant of up to €12,500 (from 3 February 2026: €6,500 heat pump + €2,000 heating system upgrade + €4,000 renewable heat bonus) applies as long as the installer is SEAI-registered and your home was built before 2021.
How quiet is the Vaillant aroTHERM plus?
It is among the quietest air-source heat pumps sold here at its low setting: Vaillant publishes sound power from the high-20s to mid-40s dB(A) depending on output, and several output sizes carry Quiet Mark accreditation. That's why we rate it first for terraced, semi-detached, and urban homes where the outdoor unit sits close to a bedroom window or a neighbour's boundary.
Vaillant or Viessmann: which should I choose?
They're the two German R-290 rivals and very evenly matched. Viessmann's Vitocal 150-A edges efficiency (SCOP up to 4.9 vs ~4.7); the aroTHERM plus edges noise, flow temperature (75°C vs 70°C), and warranty (5 years, 7 with the Advance pack). Both have small Irish networks, so the deciding factor is usually which brand your best local installer actually knows. Get both quoted.
Will I need to replace my radiators with an aroTHERM plus?
Often not. Because the R-290 refrigerant lets it reach flow temperatures up to 75°C (close to what an oil or gas boiler delivers), many retrofits keep their existing radiators, which can cut thousands off the installation cost. Your installer's heat loss survey has the final say: some undersized radiators may still need swapping for the system to run efficiently rather than just adequately.
Related Guides
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Home Energy Grants Guide
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Sources
- Vaillant: aroTHERM plus product range, vaillant.co.uk
- SEAI: Heat Pump Systems Grant, seai.ie
- SEAI: HARP database (Home-heating Appliance Register of Performance), seai.ie
Last updated: August 2026
Fact-checked by John Rooney, Solar Energy Editor. Editorial policy
John Rooney is the founder of Solar Info and has been covering the Irish solar energy market since 2023. He fact-checks all content against official SEAI data and maintains relationships with SEAI-registered installers across Ireland.
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