Grant vs Vaillant Heat Pumps

Grant and Vaillant both offer air source heat pumps for UK homes that want to move away from gas boilers. Grant's range centres on its Aerona³ system, which uses R32 refrigerant in a compact monobloc design with a quoted CoP of up to 4.65. Vaillant's comparable heat pump is rated around 4.35 CoP, with a five-year warranty against Grant's seven-year cover. Both brands are well suited to homes with existing radiators, though the sizing of the system should always be checked first.

Grant's technology centres on Aerona³ with R32 refrigerant, a CoP of up to 4.65 and a weather compensation digital controller that adjusts flow temperature to outdoor conditions. Its low-noise operation starts at 45dB(A), and the monobloc unit is compact enough for smaller gardens. Heat pumps like these can deliver heating and hot water from one system and operate down to -20°C. Vaillant's comparison figures are a CoP of 4.35 and a five-year warranty, and Grant installations may need radiator upgrades, so that cost should be factored in.

Grant suits homeowners who want the highest efficiency figure in this pairing and have space for an outdoor unit, and who are prepared for possible radiator work. Its weather compensation control suits properties where running cost matters most. Vaillant suits buyers who want a well-supported brand with very good UK support and a slightly lower efficiency figure, particularly if their existing radiators are already suitable. Either way, households should check whether the Boiler Upgrade Scheme grant applies, as it can offset a meaningful part of installation costs.

Bottom line: choose Grant if you want the higher efficiency rating of 4.65 CoP and a seven-year warranty, and have space for the outdoor unit plus possible radiator work. Choose Vaillant if you prefer a 4.35 CoP heat pump with a five-year warranty and very good UK support, and your existing radiators are already suitable for a low-temperature system.