REU-2532FFU Series 4 Rinnai
Glossary of Terms and Symbols
This glossary of terms and symbols is provided to assist you in understanding some of the
language used throughout this manual.
DB(A) - sound pressure level in decibels, “A” range
DC - direct current
AC - alternating current
WFCD - water flow control device
FB - feedback information
Hz. - hertz
IC - integrated circuit
BTU/H - British thermal units
PSI - Pounds per square inch
LED - light emitting diode
GPM - gallons per minute
mA - milliamps
W.C. - inches of water column
mm - millimeters
Nox - oxides of nitrogen NO & NO
2
OHS - overheat switch
PCB - printed circuit board
CPU - central processing unit
POT - potentiometer
rpm - revolutions per minute
SV - solenoid valve
∅∅
∅∅
∅ - diameter
∆∆
∆∆
∆
°°
°°
°F - delta T or temperature rise above ambient
POV - modulating valve
TE - thermal efficiency
TH - thermistor
T
IN -
temperature of incoming water
T
out
- temperature of outgoing water