Supply Water Thermostat (Swt) Settings Above 180°F - American Standard TGBWF090A93AVA Installation Manual

3.15 Supply Water Thermostat (SWT)
Settings Above 180°F
The adjustable SWT knob includes a factory installed rotation
stop that prevents supply water temperature settings below
140°F or above 180°F. Under no circumstances should the
SWT knob be modifi ed to allow temperature settings below
140°F. Lower settings may allow corrosive condensation from
fl ue products, decreasing the life of the boiler.
Some applications may call for supply water temperature set-
tings above 180°F. For these applications, the SWT rotation
stop may be modifi ed to allow the SWT to be set as high as
194°F. (Note: modifying the stop to allow higher maximum
setting will also result in a corresponding increase in the mini-
mum SWT temperature setting.)
Figure 54
Follow the steps below to reset the SWT rotation stop to
allow water temperature settings up 194°F:
1. Remove the knob from the adjustable SWT by pulling the
knob directly outward away from the boiler.
2. Look on the back of the knob and fi nd the metal rotation
stop in one of the numbered positions (see Figure
54). This metal stop should have been factory set to
position 1 or 7.
3. Remove the metal stop from the knob by grasping it
fi rmly with needle nose pliers and pulling it directly
outward. See Figure 55.
4. Place the metal stop in position 5 by grasping it fi rmly
with needle nose pliers (see Figure 56) and pushing it
directly inward. Note: Positions 1, 5 and 7 are the only
approved locations for the SWT rotation stop.
5. Replace the modifi ed knob by aligning with the fl at on
the shaft of the SWT and pushing fi rmly on the SWT.
Make sure that the indicator mark on the front of the
knob is between the proper modifi ed setting range
as marked on the boiler. If not, remove the knob and
rotate the shaft of the SWT as appropriate so that the
indicated adjustment range will be between approxi-
mately 155°F and 195°F.
Figure 55
Figure 56
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