Boilers with a SEDBUK Band Rating of A Have an efficiency rating in excess of ninety-percent (90%).
If you have a Standard (non-condensing) GAS Boiler already installed & would like to check it’s SEDBUK SAP rating – please view the complete, full boiler list on the SEDBUK Band A (efficiency rating of over 90%) Boiler Ratings Page!  
For your convenience…
All Regular non-condensing boilers are listed in alphabetical order on the SEDBUK Band A page..!!