|
QUESTION:I am replacing an existing boiler in a 700 sq ft house. What is the
CHEAPEST natural gas boiler I can buy of at least 60,000 BTU online or
otherwise. This seems like a question I should be able to answer with
google.com but I had back luck so I am asking the experts.
ANSWER: A lot of people use water heaters for that purpose. those
are cheap. you will have to check the btu/hr heat input
rating and select accordingly, for 60,000 btu/hr you probably
need a 30 gal high recovery rate water heater... cost probably
under 400 dollars.. could be a little more.
Then just hook it up to your hot water circulating pump...dont
forget to fit an expansion tank.. the bladder diaphram type
will be best for your application, a small one, about 5 gal
total capacity... no valves between the expansion tank and the
hot water outlet of the heater. you can locate the bladder
type anwhere you want...be sure to read the directions.
That should last you about 10 years, maybe 20 years in house
heating service conditions.... its a closed loop, so there
will not be any scale build up issues.
You might consider a 40,000 btu model for a house that small,
then suppliment with a 50 dollar electric heater in your
bedroom for cold nights on occasion. that would be about
200 dollars cheaper.
Is it legal? check your local city building inspectors dept.
they may require you to fit an approved **low water safety
shut off*** , but maybe not... the smaller you go the less is
required for ignition and low water protection...an advantage
if you go to the 20 gallon heater. Be sure to fit the
standard hot water heater pressure relief valve regardless
..thats critical.
The city may want a back flow preventer on the cold water make
up line. you may or may want to ask, since its somewhat of a
self sterilizing loop if you set the thermostat over 200F...
and you will not be treating it with chemicals that is not
entirely critical issue (as it is with larger boilers that
chemically treated water in loop that you want to keep out of
the city mains in event of loss of city water pressure etc).
There are bacteria that live in hot water though and you
wouldnt want that back flushing into your city water line, so
minimally I would install a swing check valve... and discuss
it with the city.
If someone sets the thermostat below 120F you can get
dangerous bacteria growing in the heater and water
distribution lines...and that could happen later, after you
are gone etc.
Buy it for the correct fuel, natural gas or propane. they
have different jet sizes.
|
|
|
|
