I have a Valor Bolero inset gas fire,fitted ten years ago.A Valour engineer serviced it a year ago.I mentioned to him the heat output was markedly less than when it was new.He said after servicing,the fire was within the makers spec for performance.i had the idea of trying to check myself.Imeasured the gas used in exactly one hour, on full.by reading the meter.
I used the formula :Cu Ft gasX3.6=Kw
my result was3.3Kw
I see the fire spec says max input 6.8Kw, min input 2.2kw
Am I right in thinking ,based on this result the fire is not working properly?