Great customer service! very trustworthy people!! Fortunately, gr plumbing is a commercial and residential. The good thing about most boilers these days is that they’re sold at around % efficiency give or take a couple of percentage points in fact, if you have a really old, inefficient boiler, a new one could save you up to £! Find cheap pick-up only items near you - they often attract fewer bids. Brian does an amazing job and his prices are very fair.