Instruction manual
41
TABLE 18.   
WATER HARDNESS MEDIUM (0-12 GRAINS PER GALLON)
XW MODEL 
NO.
∆T ºF GPM ∆P FEET
1000 25 76 17.5
1300 25 99 22
1700 25 129 23
2000 25 152 17.5
2600 25 198 22
3400 25 258 23
∆T ºF = Temperature rise ºF at the specied GPM.
GPM = Flow rate in gallons per minute.
∆P = Pressure loss through the heat exchanger in feet of head.
For  systems  over  5  grains  per  gallon;  and  for  scale  free  
operation, boiler setpoint should not exceed 140 ºF.
Note:  The  factory  installed/supplied  pump  on the  above listed 
model boilers is sized to maintian a 25 ºF ∆T through the boiler 
when the boiler is ring at 100% re.
In  addtion  to  the  pressure  loss  through  the  heat  exchanger, 
the factory supplied pump is sized  for an additional 50 feet of 
equivalent feet of piping between the boiler and a storage tank. 
All  piping between the  boiler and the storage  tank must be  of 
a  pipe  size  equal  to  the  inlet/outlets  of  the  boiler.  Installation 
differences may slightly change these parameters.
FREEZE PROTECTION (HYDRONIC HEATING 
INSTALLATION)
1.  Determine  freeze  protection  uid  quantity  using  system 
water content, following uid manufacturer’s instructions. 
2.  Local  codes  may  require  a  backow  preventer  or  actual 
disconnect from city water supply. 
3.  When using freeze protection uid with automatic ll, install 
a water meter to monitor water makeup.  Freeze protection 
uid may  leak  before the  water begins  to leak,  causing 
concentration to drop, reducing the freeze protection level.
INSPECT/FILL CONDENSATE SYSTEM
Inspect/check condensate lines and ttings:
1.  Inspect the condensate drain line, condensate PVC ttings 
and condensate trap.
Fill condensate trap with water:
1.  Remove the 2 inch PVC cap with the switch located at the 
top of the trap. 
2.  Fill with fresh water until the water begins to pour out of the 
drain. 
3.  Replace the cap.  Press the cap onto the trap until the cap 
makes contact with the drain. 
The condensate trap must be lled with water during all times of 
boiler operation to avoid ue gas emission from the condensate 
drain line.  Failure to ll the trap could result in severe personal 
injury or death.
HOT WATER CAN SCALD:  Boilers are intended to produce hot 
water.   Water heated to a  temperature which will satisfy space 
heating, clothes  washing, dish  washing  and other  sanitizing 
needs  can  scald  and  permanently  injure  you  upon contact.  
Some people  are  more likely to  be  permanently injured by  hot 
water than others. These include the elderly, children, the inrm 
or physically/mentally disabled.  If anyone using hot water in your 
home ts into one of theses groups or if there is a local code or 
state law requiring a specic temperature water at the hot water 
tap, then you must take special precautions. In addition to using 
the  lowest  possible  temperature  setting  that  satises  your  hot 
water needs, a means such as a mixing valve  should be  used 
at the hot water taps used by these people or at the hot water 
supply  tank.    Mixing  valves  are  available  at  plumbing  supply 
or hardware stores.    Follow  the  manufacturer’s instructions  for 
installation of the valves. Before changing the thermostat setting 
on the hot water system controller, refer to Table 17.
Hot  water  temperatures  required  for  automatic  dishwasher 
and laundry use  can cause scald  burns resulting in serious 
personal  injury  and/or  death.  The  temperature  at  which  injury 
occurs varies with the person’s age and time of exposure. The 
slower response time of children, aged or disabled persons 
increases  the  hazards  to  them.  Never  allow  small  children  to 
use  a  hot  water  tap,  or  to  draw  their  own  bath  water.  Never 
leave  a  child  or  disabled  person  unattended  in  a  bathtub  
or shower.
The boiler should be located in an area that is inaccessible to the 
general public.
TABLE 17.  RISK OF SCALDS
Water Temperature
Time to Produce 2nd & 3rd
Degree Burns on Adult Skin
180°F (82°C) Nearly instantaneous
170°F (77°C) Nearly instantaneous
160°F (71°C) About 1/2 second
150°F (66°C) About 1-1/2 seconds
140°F (60°C) Less than 5 seconds
130°F (54°C) About 30 seconds
120°F (49°C) More than 5 minutes
Should overheating occur or the gas supply fail to shut off, turn 
off the main manual gas shutoff valve to the boiler.
CHECK/CONTROL WATER HARDNESS
XW Model XP Boilers are approved for use in Domestic Water 
Heating Systems with a water supply hardness of  0 grains per 
gallon to a maximim of 12 grains per gallon. Refer to Table 18 for 
recommend ow rate to maintain scale free operation with up to 
a medium water hardness. For scale free operation in hard water 
systems with a water hardness greater than 12 grains per gallon, 
a water softener must be installed and maintained.










