What did you do to get it working then? If it is still raining, please give it until an hour after the rain has stopped to give the water a chance to drain naturally. Is your old boiler on the blink, and you have no hot water ? I use drainbo at the beginning of every month and i have had no problems since i started using it on a regular basis. Great group here , fast and reliable ! The boys at asap are excellent. Combi boilers: is a combi boiler the right boiler for you? If you are looking to live.