Heating Options/Opinions for North East? Replacing steam heat?

Jamie Hall

Steam boiler size is related to the amount of radiation which is attached to it -- measured in "EDR". There are tables available on this site to look up that for your radiators. The procedure is to add up the EDR of all the radiators and compare that to the EDR rating of the boiler.

The actual heat loss of the structure is of little importance with steam -- provided only that there is enough radiation to compensate for it.

Now there are two possibilities. One is that, having tightened up the house to reduce your heat loss you now have more radiation than you need. This isn't a problem; it just will mean that the boiler won't run as often. On the other hand, it may well be that the boiler is oversized -- a lot of them are -- and that is less efficient; properly sizing the boiler will save fuel. Would it save enough to pay for a new boiler? Problematic, unless the existing boiler needs replacement for some other reason.