Sparkling clean with less scrubbing – find another use for your elbow grease. We’re professional looking dudes and we keep your home clean when we’re in it! Every single one of their greenstar gas boilers has been awarded a which? best buy with our year warranty thrown in, there's no better choice for your central heating. Many claims have been made about the unit’s payback period but it’s very hard to work out without precise details and these will alter from property to property your best bet.