You can contact baxi at the following address. If drain replacement is unavoidable, our civil engineering team will plan the works to keep disruption to a minimum. If necessary, a local authority can carry out the work themselves and then charge you for it. One good indicator is looking at the boiler flame – which should be a healthy blue if it is yellow or orange then the boiler may not be getting enough gas, or conversely if it is getting too much gas, then this could be a more.