Operating instructions
 User’s Information Manual 
Please read before proceeding
The Cadet Heating Boiler Installation and 
Service Manual is for use only by a qualified 
heating installer/service technician. Refer 
only to this User’s Information Manual 
for your reference. Improper installation, 
adjustment, alteration, service or 
maintenance can cause property damage, 
personal injury (exposure to hazardous 
materials) or loss of life. Installation and 
service must be performed by a qualified 
installer, service agency or the gas supplier 
(who must read and follow the supplied 
instruction before installing, servicing, or 
removing this boiler. This boiler contains 
materials that have been identified as 
carcinogenic, or possibly carcinogenic, to 
humans).
Failure to adhere to the guidelines on this 
page can result in severe personal injury, 
death, or substantial property damage.
Boiler service and maintenance –
• To avoid electric shock, disconnect electrical supply 
  before performing maintenance.
• To avoid severe burns, allow boiler to cool before 
 performing maintenance.
Boiler operation –
• Do not block flow of combustion or ventilation air to 
  the boiler. This boiler is equipped with a control which 
  will automatically shut down the boiler should air or 
  vent be blocked. If vent or air blockage is easily 
  accessible and removable, remove it. The boiler should 
  attempt to restart. If blockage is not obvious or cannot 
 be removed, have the boiler and system checked by a 
  qualified service technician.
• Should overheating occur or gas supply fail to shut off, 
  do not turn off or disconnect electrical supply to the 
  circulator. Instead, shut off the gas supply at a location 
  external to the appliance.
• Do not use this boiler if any part has been under water.  
  The possible damage to a flooded appliance can be 
  extensive and present numerous safety hazards. Any 
  appliance that has been under water must be replaced.
Boiler water –
• Thoroughly flush the system (without boiler 
  connected) to remove sediment. The high-efficiency 
  heat exchanger can be damaged by build-up or 
  corrosion due to sediment.
• Do not use petroleum-based cleaning or sealing 
  compounds in the boiler system. Gaskets and seals in 
 the system may be damaged. This can result in 
  substantial property damage.
• Do not use “homemade cures” or “boiler patent 
  medicines”. Serious damage to the boiler, personnel, 
  and/or property may result.
• Continual fresh make-up water will reduce boiler life.  
  Mineral buildup in the heat exchanger reduces heat 
  transfer, overheats the stainless steel heat exchanger, 
  and causes failure. Addition of oxygen carried in by 
  makeup water can cause internal corrosion. Leaks in 
  boiler or piping must be repaired at once to prevent 
 makeup water.
Freeze protection fluids –
• NEVER use automotive antifreeze. Use only inhibited 
 propylene glycol solutions, which are specifically 
  formulated for hydronic systems. Ethylene glycol is 
  toxic and can attack gaskets and seals used in hydronic 
 systems.
When calling or writing about the boiler 
– Please have the boiler model and serial 
number from the boiler rating plate.
Consider piping and installation when 
determining boiler location.
Any claims for damage or shortage in 
shipment must be filed immediately 
against the transportation company by the 
consignee.
Factory warranty (shipped with unit) does 
not apply to units improperly installed or 
improperly operated.
3
 NOTICE
 WARNING
 NOTICE
DO NOT install units in rooms or 
environments that contain corrosive 
contaminants (see Table 1A on page 4).  
Failure to comply could result in severe 
personal injury, death, or substantial 
property damage.
 WARNING










