I had my boiler serviced in late November 2017 and this was done through my household insurance - previously I had a plan with British Gas that cost me "an arm and a leg". At the service I mentioned that the heating took forever to warm up and most radiators were cold at the bottom. At the end the engineer said that he had cleaned out the burners and that should make matters better. Well unfortunately it didn't so tried to get that company back - they would have attended but charged me £95 per hour plus parts! Decided to have a power flush of the system as it had never been cleaned in the 30 years that we had lived in the house. The power flush made some difference to the radiators getting warmer at the bottom but it didn't resolve the issue of how long it took to warm up - in fact when it was really cold we ended up having the heating on low all night just to keep the house aired. Matt from the power flush company recommended Nathan and he attended on 12 February. He quickly identified that there was an issue with the gas flow as it was very low. Despite the service in November he still found lots of debris in the boiler so gave everything a good clean out. Heating is now very warm. Will be using Nathan again.