I have heard that there could be alternatives to having hatches fitted. Is this true?

Visual examination checks by engineers via inspection hatches is currently the preferred method recommended by the industry guidance that explains how to judge that a flue is working safely and effectively. However, where inspection hatches are not practicable industry has developed a safety system which is able to monitor the void for the presence of carbon monoxide and which cause the boiler to shut down if it is detected. If you want to see what these devices look like click on this link.http://www.installeronline.co.uk/baxi-launches-carbon-monoxide-monitoring shut-off-system/

Ms Jones, ME14