Hoping someone can give me advice with this one. At an annual gas service today I found a Worcester Greenstar Junior 28i to be using only running at around 12kW on high when carrying out the gas rate. The CO readings were where they should be, fan speed was okay and inlet working pressure was 22mbar. Can anyone suggest what the problem might be? What was strange to me was the fact that the hot water quality was great with great flow rate. In my experience hot water quality drops significantly when the gas rate is cut back. Part of me thinks there might be an issue with the meter but I’m still quite new to the industry and always looking for input from experienced engineers. Any advice would be greatly appreciated.