Every contractor i talked to said this is the best boiler they have installed! View previously purchased products. Can i put drain out bathroom down the drain after using another drain cleaner? Whatever system you’re replacing, the incoming boiler will be a condensing one. Radon mitigation systems: is your home safe? Opportunities for plumbers, gasfitters and drainlayers are good due to. With no water tank to heat up, combi boilers can provide an unlimited supply of hot water on demand no waiting.