Can drain out bathroom be used in a toilet? In the event that the boiler needs a replacement part, our team of repair engineers carry a range of high quality parts with them so that in most cases, the gas boiler can be repaired on the same visit. We would highly recommend all koegel plumbing services without hesitation! You could win a $, mitre gift card. With no water tank to heat up, combi boilers can provide an unlimited supply of hot water on demand no waiting time! We promise to meet and exceed.