There isn't a 'best boiler for underfloor heating' as many boilers and heat pump solutions offer a wide range of different benefits. However, we would recommend either a condensing boiler or a dedicated air source heat pump. A condensing boiler operates at temperatures that complement warm water underfloor heating solutions. An air source heat pump is a low-carbon heat source that is incredibly efficient at producing low flow temperatures which also work well with underfloor heating.