Bissell ProHeat 2X Revolution Pet Pro (model 20666)

This is the one upright on our list that both keeps its wash water warm through the clean and gives you a dedicated pre-treat trigger, and that pairing is why it tops the ranking. Bissell's HeatWave technology is not an onboard heater and does not warm cold water: you fill the tank with warm tap water (Bissell specifies 60C max), and HeatWave recirculates motor heat to hold that temperature during cleaning rather than letting it cool - so it stays warm enough to help dissolve set-in pet grease and stains as you work. The CleanShot function sprays concentrated solution straight onto tough spots before you make the main pass. Dual rotating DirtLifter PowerBrushes and an 800W motor do the lifting, an Express Clean mode is quoted to dry carpets in around 30 minutes, and the 3.7L clean-water tank - the largest here - means fewer refill trips on whole-house jobs. It ships as a genuine pet bundle with a pet tool and pet-odour formula. The Bissell UK product page lists a 6-year warranty, which is longer than the brand's usual cover, so confirm it at checkout. Price is indicative at £249.99 (reduced from £299.99) and it weighs 7.94kg.