Viessmann Heat Pumps Review: Vitocal 150-A for Irish Homes
Viessmann is a German heating manufacturer with over a century of history, and its Vitocal 150-A air to water heat pump is one of the most efficient units you can put on an Irish house. Here's our independent review: the specs that matter, what it costs installed, SEAI grant eligibility, and how it compares to Daikin, the brand most Irish installers quote first.
Quick Answer
Viessmann heat pumps are a premium German option for Irish homes. The flagship Vitocal 150-A is an air to water monobloc with a published SCOP of up to 4.9, R-290 propane refrigerant, and flow temperatures up to 70°C, high enough that many retrofits keep their existing radiators. Expect €12,000–€16,000 installed before the SEAI grant of up to €12,500. Viessmann models are on the SEAI approved product list, so the grant applies in full. The trade-off is a smaller Irish installer and service network than Daikin or Mitsubishi.
Who Are Viessmann?
Viessmann was founded in 1917 in Germany and is one of Europe's largest heating technology manufacturers. Irish homeowners may know the name from gas boilers; its climate solutions division (now part of Carrier Global) has shifted hard into heat pumps, with the Vitocal range as the flagship.
In Ireland, Viessmann heat pumps are newer to the market than Daikin or Mitsubishi and are sold through a national distributor network rather than direct. That matters in two ways: the installer pool is smaller, and aftercare depends more on your installer than on a manufacturer-run service network. The hardware itself is among the best specified on the market.
1917
Founded (Germany)
4.9
SCOP (Vitocal 150-A)
70°C
Max flow temperature
R-290
Natural refrigerant
Viessmann Vitocal 150-A Specifications
The Vitocal 150-A is the model Irish installers quote for retrofits: an air to water monobloc designed specifically for modernisation projects, where the house keeps its radiators and hot water cylinder layout. The Vitocal 151-A is the same heat pump paired with a floorstanding indoor unit that integrates the hot water cylinder, a neater fit where the old boiler and cylinder are coming out together.
| Specification | Vitocal 150-A |
|---|---|
| Type | Air to water, monobloc |
| Rated output range | 2.6–14.9 kW |
| SCOP | Up to 4.9 |
| COP | Up to 5.0 (at A7/W35) |
| Max flow temperature | 70°C |
| Refrigerant | R-290 (propane, ultra-low GWP) |
| SEAI approved product list | Yes, grant eligible |
| Warranty | Up to 5 years (installer-dependent) |
Source: Viessmann Vitocal 150-A/151-A product documentation. Confirm the exact model code and warranty terms on your quote. Warranty length depends on the installer's registration with Viessmann.
Why the 70°C flow temperature matters
Most heat pumps run radiators at 35–55°C, which is why retrofits often need bigger radiators. The Vitocal 150-A can push 70°C on cold days, close to what an oil or gas boiler delivers, so more retrofits keep their existing radiators, cutting thousands off the installation cost.
Why R-290 matters
R-290 (propane) is a natural refrigerant with a fraction of the global warming potential of the R-410A and R-32 blends in older units, and it is what enables the high flow temperatures. EU F-gas rules are phasing synthetic refrigerants down, so R-290 units are the more future-proof buy.
Viessmann Heat Pump Cost in Ireland
Expect €12,000–€16,000 fully installed for a Vitocal 150-A system, depending on house size, cylinder work, and whether any radiators change. That puts Viessmann at the premium end alongside Nibe and Vaillant, though the high flow temperature can claw money back on retrofits by avoiding radiator upgrades.
Viessmann models are on the SEAI approved product list, so the full grant of up to €12,500 (from 3 February 2026: €6,500 heat pump unit + €2,000 central heating upgrade + €4,000 renewable heat bonus) applies when an SEAI-registered installer fits it in a home built before 2021. 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.
Viessmann vs Daikin: Which Is Better for Ireland?
This is spec sheet vs service network. Viessmann edges the numbers; Daikin wins on installer availability:
| Feature | Viessmann Vitocal 150-A | Daikin Altherma 3 |
|---|---|---|
| SCOP | Up to 4.9 | ~4.6 |
| Max flow temperature | 70°C | Up to 70°C (H HT variant) |
| Refrigerant | R-290 | R-32 |
| Installed cost | €12,000–€16,000 | €11,000–€15,000 |
| SEAI grant | Up to €12,500 | Up to €12,500 |
| Irish installer network | Small but growing | Largest in Ireland |
| Warranty | Up to 5 years (installer-dependent) | 5 years (extendable to 7) |
Verdict: on paper the Vitocal 150-A is the stronger unit: higher SCOP, natural refrigerant, boiler-like flow temperatures. Daikin remains the safer pick where local service coverage matters most, because almost every county has multiple Daikin-experienced installers. If a competent installer near you fits Viessmann, it deserves a quote alongside Daikin.
Viessmann Heat Pumps: Frequently Asked Questions
Are Viessmann heat pumps any good?
Yes. The Vitocal 150-A has one of the highest published SCOPs of any air to water heat pump sold in Ireland (up to 4.9), uses R-290 natural refrigerant, and reaches 70°C flow temperatures, which means many retrofits keep their existing radiators. The main caveat is a smaller Irish installer and service network than Daikin or Mitsubishi.
How much does a Viessmann heat pump cost in Ireland?
Expect €12,000–€16,000 fully installed for a Vitocal 150-A air to water system before the grant. After the SEAI grant of up to €12,500, the net cost for qualifying homes falls substantially. Retrofits that keep their existing radiators (thanks to the 70°C flow temperature) land at the lower end.
Is the Viessmann Vitocal 150-A eligible for the SEAI grant?
Yes. Viessmann Vitocal models are on the SEAI approved product list. The grant of up to €12,500 applies as long as the installer is SEAI-registered and your home was built before 2021.
Viessmann or Daikin: which should I choose?
Viessmann edges the spec sheet: higher SCOP (4.9 vs ~4.6), R-290 refrigerant as standard, and 70°C flow. Daikin has by far the bigger Irish installer and service network, which matters for aftercare over a 15–20 year life. If you have a strong local Viessmann installer, get both quoted.
Is Viessmann better than Vaillant?
On paper the Vitocal 150-A edges the Vaillant aroTHERM plus: SCOP up to 4.9 versus around 4.7, and a 70°C maximum flow temperature versus 75°C for Vaillant, both on R-290. Vaillant has the larger Irish installer base and is the quieter unit at low load; Viessmann wins on peak efficiency and retrofit flexibility. Both are SEAI grant eligible. See our Vaillant aroTHERM plus review and get both quoted if you have installers for each nearby.
Who installs Viessmann heat pumps in Ireland?
Viessmann heat pumps are sold through a national distributor network and fitted by SEAI-registered installers who have trained on the brand. The installer pool is smaller than Daikin's. Ask specifically for the Vitocal 150-A when requesting quotes and confirm the installer's Viessmann experience.
What is the difference between the Vitocal 150-A and 151-A?
Same heat pump, different indoor unit. The 150-A pairs with a wall-mounted indoor unit and your existing or separate hot water cylinder; the 151-A uses a floorstanding indoor tower with the cylinder built in, the tidier option when the old boiler and cylinder are being removed together.
Related Guides
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Full price breakdown: €9,000–€14,000 installed, net cost after the €12,500 grant.
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Home Energy Grants Guide
All SEAI home energy grants: eligibility, amounts, and step-by-step application.
Sources
- Viessmann: Vitocal 150-A product range, viessmann.co.uk
- SEAI: Heat Pump Systems Grant, seai.ie
- SEAI: Approved Product Lists, 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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