Instruction manual
22
LEVELING
Because this unit is a Category IV appliance it produces some 
amounts of condensation. The unit has a condensation disposal 
system that requires this unit to be level to properly drain. Each 
unit should be checked to be certain that it is level prior to starting 
the unit.
If the unit is not level, obtain and insert shims under the feet at 
the frame base to correct this condition.
AIR REQUIREMENTS
Breathing Hazard - Carbon Monoxide Gas
Install appliance in accordance with
the Instruction Manual and NFPA 54 or
CAN/CSA-B149.1.
To avoid injury, combustion and ventilation
air must be taken from outdoors.
Do not place chemical vapor emitting
products near water heater.
Breathing carbon monoxide can cause brain damage or
death. Always read and understand instruction manual.
For safe operation an adequate supply of fresh uncontaminated 
air for combustion and ventilation must be provided.
An insufcient supply of air can cause recirculation of combustion 
products  resulting  in  contamination  that  may  be  hazardous  to 
life. Such a condition often will result in a yellow, luminous burner 
ame, causing sooting of the combustion chamber, burners and 
ue tubes and creates a risk of asphyxiation.
Do not install the boiler in a conned space unless an adequate 
supply of air for combustion and ventilation is brought in to that 
space  using  the  methods  described  in  the  Conned  Space 
section that follows. 
Never obstruct the ow of ventilation air. If you have any doubts 
or questions at all, call your gas supplier. Failure to provide the 
proper amount of combustion air can result in a re or explosion 
and cause property damage, serious bodily injury or death.
UNCONFINED SPACE
An unconned space  is one whose volume is not less than 50 
cubic  feet  per  1,000  Btu/hr  (4.8  cubic  meters  per  kW)  of  the 
total input rating of all appliances installed in the space. Rooms 
communicating directly with the space, in which the appliances 
are  installed,  through  openings  not  furnished  with  doors,  are 
considered a part of the unconned space.
Makeup air  requirements for the  operation of exhaust  fans, 
kitchen ventilation systems, clothes dryers  and  replaces  shall 
also be  considered  in determining the  adequacy  of a space  to 
provide combustion, ventilation and dilution air.
UNUSUALLY TIGHT CONSTRUCTION
In unconned spaces  in buildings, inltration  may be adequate 
to provide  air  for combustion,  ventilation and  dilution of  ue 
gases. However, in buildings of unusually tight construction (for 
example,  weather  stripping,  heavily  insulated,  caulked,  vapor 
barrier, etc.) additional air must be provided using the methods 
described in the Conned Space section that follows.
PANELS AND COVERS
All panels and covers (e.g. control and junction box covers; front, 
side and rear panels of boiler) must be in place after service and/
or before opera tion of boiler. This will ensure that all gas ignition 
components will be protected from water.
The  XP  is  a  low-pressure  boiler  (Category  IV)  to  be  used  as 
either hot water supply (domestic/commercial water heating) or 
hot water heating (hydronic) application. Category IV appli ances 
are often termed “High Ef ciency” appliances.
CHEMICAL VAPOR CORROSION
Boiler corrosion and component failure can be caused by the 
heating and breakdown of airborne chemical vapors.  Spray can 
propellants, cleaning sol vents, refrigerator and air conditioning 
refrig erants,  swimming  pool  chemicals,  calcium  and  sodium 
chloride  (water  softener  salt),  waxes,  and  process  chemicals 
are  typical  compounds  which  are  potentially  corrosive.  These 
materials are corrosive at very low concentration levels with little 
or no odor to reveal their presence.
Products of this sort should not be  stored near  boiler. Also, air 
which  is  brought  in  contact  with  boiler  should  not  contain  any 
of these chemicals. If necessary, uncontaminated air should be 
obtained from remote or outside sources. Failure to observe this 
requirement will void warranty. 
INSTALLATION CLEARANCES
This boiler is approved for installation in an alcove with minimum 
clearances to combustibles.
TABLE 12.  INSTALLATION CLEARANCES
RECOMMENDED 
SERVICE 
CLEARANCES
CLEARANCES FROM  
COMBUSTIBLE 
MATERIALS
Front 30" (762 mm) 8" (203 mm)
Rear 36" (610 mm) 24" (610 mm)
Left 24 " (610 mm) 1" (25.4 mm)
Right 24 " (610 mm) 2" (51 mm)
Top 24" (610 mm) 6" (152 mm)
 2” (51 mm) clearance is allowable from combustible construction 
for hot water pipes.
Sufcient  area  should  be  provided  at  the front and  rear  of  the 
unit  for  prop er  servicing.  In  a  utility  room  installa tion,  the  door 
opening  should  be  wide  enough  to  allow  the  boiler  to enter or 
to permit the replacement of another appli ance such as a boiler.
FLOORING AND FOUNDATION:
All models are approved for installation on combustible ooring, 
but must never be installed on carpeting. Do not install the boiler 
on carpeting even if foundation is used. Fire can result, causing 
severe personal injury, death, or substantial property damage. 
If  ooding  is  possible,  elevate  the  boiler  sufciently  to  prevent 
water from reaching the boiler.










