HTP SSU-119CB - Manual (Page 9)

9
LP-32 Rev. 3.25.14
E. POTABLE EXPANSION TANK
A thermal expansion tank is required in the system designed for potable water use, to offset the expansion of stored water as the
temperature is elevated.
PART 4 – CONTROL AND WIRING
A. CONTROL
A pre-wired surface mount control is provided on your storage tank. Temperature may be set by removing lower cover screw and lower
cover. VERY IMPORTANT: SEE SCALDING NOTE ON PAGE 10.
B. WIRING
All wiring is to be done in accordance with all applicable local and state codes. Turn off all power related to the boiler before starting any
wiring procedures.
Figure 4 – Wiring the Control
PART 5 – OPERATING THE STORAGE TANK
Boiler high limit should be set at least 20
o
F higher than the storage tank temperature setting. Set the low limit of the boiler control at the
minimum setting – this will call the burner on only to satisfy the tank control.
We recommend a storage tank temperature setting of 120
o F. However, a lower temperature setting may be required to comply with
local and state codes for normal operation. You may prefer a setting of either higher or lower water temperature. A mixing valve in
conjunction with a high temperature setting may be used for high demand applications (spas, hot tubs, whirlpools).
If draining of the storage tank is necessary, open the temperature and pressure valve or a hot water tap to prevent vacuum buildup in
the tank and piping.
A temperature limiting or mixing valve is not entirely necessary, but recommended in installations servicing disabled or elderly persons,
or children. Take extreme caution to avoid scalding when temperature limiting or mixing valves are not used.