BoilerMan
Minister of Fire
I have no idea I only used oil for two year when we first moved in. Then I put a woodstove in. A heating contractor could do a test couldnt they. Does it have to be cold out to do the test?
Yes and no.
Yes a good heating contractor is able to do a pretty accurate heat loss calculation. There is also software that you can plug in numbers into that will get you pretty close.
No is doesn't have to be cold outside, it is only a calculation based on construction type, window type and size etc. You may be thinking of an IR imaging camera used to "look for heat loss".
TS