CB
Built Like A Tank With Laser Precision
Page
10
of 24
G. Heating Domestic Hot Water
To heat your domestic hot water, water from the outdoor boiler is circulated through a “water to water”
heat exchanger which is connected to your existing hot water heater. This is either a plate or side-arm
style heat exchanger. The hot water from the boiler usually goes to the exchanger at your hot water
heater and then to the exchanger on your furnace. You may use either style exchanger with your hot
water heater. If heating your home through a radiant system, first go through the exchanger for your
old boiler system, then through the exchanger for your domestic hot water heater. Reverse this
sequence for forced air systems. See page 19 for a layout of piping for a sidearm.
H. Thermostat, Boiler Controls
The only visible addition to the heating system inside your home is a second thermostat, which should
be located near the existing thermostat. This second thermostat needs to be installed to operate your
existing blower for forced air or your circulation pump for radiant heat and needs to be set higher that
your original thermostat so your existing furnace will automatically take over to maintain your
household temperature if your boiler is not running. Please see page 18 for an example wiring layout.
The outside boiler has a hot water thermostat (aquastat) with a thermocouple that is inserted into a
brass drywell that senses the water temperature of the boiler. When the temperature of water in the
boiler falls below the “low” temperature setting on the aquastat, the solenoid lifts the cover off the
blower which turns on, feeding oxygen to build a hotter fire and remains on until the water temperature
in the boiler reaches the “high” temperature setting of the aquastat. Temperature may be set anywhere
between 100 – 180 degrees F. Do not set above 180F. When heating your home through a radiant
system, the recommended setting is 180. When heating with a forced air system, the recommended
setting is 140. The aquastat also has a temperature swing setting that is adjustable from 5 – 30
degrees. Recommended setting is 12 degrees which provides for a longer burn cycle resulting in less
creosote buildup.
