All condensers do is move heat. So they take the heat out of the interior of you house, to the hot water. Now we have to heat the house again.
that is during the winter, in summer might be ok.
more useful in the south
But the govt is one size fits all, they never look at the system, only the most perfect hypothetical situation.
Yes & no.
See my #21.
Not exactly.
A condensing heating device is simply one that extracts enough heat to lower the exhaust flue temperature into the water condensing range. Different sources make different claims, typically from ~250F and lower, some can approach an exhaust temperature slightly lower than the discharge temperature of the heated media.
And for some fun check the recommended temperature to prevent Legionella and the max safe hot water discharge temperature.
Lower domestic hot water temperatures are more efficient but tend to promote Legionella.