Uncertain how energy efficient your new boiler will be in reality? this blog might help shed some light on the subject the good news is that all boilers are around % efficient, maybe give or take a couple of percentage points depending on the model and brand you choose however, it’s how you use it that’s important! When you take out one of our annual sse boiler or heating cover plans at the same time (excludes sse boiler breakdown and sse heating breakdown). You have an incredible team! my suite.