FIG.7-TYPICALTANKLESSCOILPIPING
II
Use the following setting for the first adjustment:
High Setting .............. 180°F
Low Setting ............... 160°F
Differential .................. 20°F
These settings may be altered based on the heating
system response. During very cold weather if the
heating system does not provide quite enough
heat, the high limit control setting may be raised to
a maximum of 200°F. If more domestic hot water is
required, the low limit control setting may also be
raised to a maximum of 180°F. Whenever adjusting
either the high or low limit, the high limit control
setting must be set at least 20°F above the low
limit. The differential control setting is typically 20°F
but may be adjusted to vary the time it takes the
burner to respond to a call for domestic hot water.
1. Cold standby is suitable only when thermostatic
union is used with piping bypass shown in Figure 6.
2. A change in control wiring is also required. To
prevent excessive condensation, please contact
factory before making this change.
3. Owners of non-tanktess boilers often object to the
burner starting when space heat is not required. To
avoid this, an optional outside thermostat may be
used to shut down the system totally when outside
temperature is above a specific limit set by the
homeowner. See wiring diagrams.
_sb,MPORTANT: Instruction manual enclosed i!_
umer carton must be followed in regard t
tartup and adjustment.
1. STANDARD BECKETT AFG OR CF375
OIL BURNER: A Beckett model ADF oil burner
is normally supplied with boilers to be fired at
2.00 gph or less. It is equipped with an F3 flame
retention head, the size most commonly used. It is
possible the head must be changed to match the
nozzle firing rate required, and it is recommended
the installer carry a complete assortment of Beckett
flame retention heads. When head rating overlap,
a smaller head with air shutter fairly well open
will generally provide better combustion than a
larger head with air shutter near closed. See head
size selection chart in this manual. For Beckett
burners at firing rates above 2.00 gph, a Beckett
model CF375 burner is required, and is supplied if
specified by purchaser.
2. OPTIONAL RIELLO 40 SERIES OIL BURNER:
Riello 40 series oil burner is optional. Model F5
is used for firing rates from 0.90 to 1.50 gph, and
Model F10 is used for firing rates from 1.60 to 3.00
gph. Model F5 or F10 is supplied if specified by
purchaser. For firing rates below 0.90 gph, a Model
F3 is required, and must be purchased from a Rietto
distributor.
/'-SUGGESTED NOZZLES, HEADS, AN D"_
PRELIMINARY SETTINGS FOR VARIOUS I
BURNERS AND FIRING RATES ARE SHOWN I
,..ON THE FOLLOWING PAGES. J
3. On knockdown boilers, the burner is not supplied
with a nozzle. The correct nozzle is the smallest
which will do the job properly. Long continuous runs
with minimum starts and stops conserve the most
energy. The nozzle which provides the highest C0_
with the least smoke for a particular application
is always recommended. Beckett oil burners are
supplied with pump pressure set at 140 psi. Nozzle
output will be approximately 18% greater than that
at 100 psi. Pump pressure on Rietto burners should
be adjusted according to settings in "Suggested
Nozzles and Settings for Riello Burners" on the
next page.