"The Natural Philosopher" wrote in message
...
Roger Mills wrote:

Does your boiler also need to provide domestic hot water? If so, add
a further 15,000-20,000 BThU/Hr.



NOTE: This does not compute if you have a hot water tank. You need very
little to heat a tank - maybe 500-600W. You DO need a lot of its a
comnbi system trho, since it has to het the water onthe fly,..but most
of these seem to chop the heating whilst the bath is running anyway...







I'm sure that 15,000 BThU/Hr (about 4.4 KW) had used to be the
recommendation for DHW. This would heat a 30 gallon tank from cold to 140
deg F (60 deg C) in about 2 hours. Your 500-600 watts ( 2000 BThU/Hr) would
take 15 hours or so - no use if several people want baths!

Roger