Smart controls can help with that in fact, you could increase your boiler’s efficiency by an extra %! pretty nifty, eh? You’ll be interested to hear that every worcester bosch boiler we install, comes with an unbeatable choice of guarantees - you may choose between , & years cover - now imagine no boiler repair bills for the next years! Quality, reliability, expertise. Is it recommended to ask for references from a plumber? The permissible capacity of your timer in.