Furnace FAQ's

• Can I put air conditioning on this unit? 
  Yes, LDJ furnaces are factory ready to add air conditioning.
• What size A/C can I connect to my furnace? 
  The LDJ A-Maize-Ing Heat Furnace can accommodate up to a four ton air conditioner provided the duct system and static pressure fall under the design criteria required.
• Does it require a special A/C coil?
  No, our normal supply air temperatures are 150°-180°F with a high limit lock out at 200°F. A standard air conditioning coil may be used.
• How much air can the furnace move? 
  Max air flow is 1600 cfm at .075 sp. For other air flows please contact your dealer.
• Can I connect into my existing furnace? 
  Yes, the furnace can be ducted in parallel with your existing system by utilizing a backdraft damper. Please consult your dealer or a certified HVAC contractor.
• What type of thermostat should I use? 
  LDJ recommends a digital 24 volt thermostat. For other types please contact your dealer.
• How often should I change my filter?
  LDJ recommends that you change your air filter every 2-3 months or as needed.
• Can I connect this to a zone control system? 
  Yes, you will need to consult your dealer or a certified HVAC contractor.
• Why does my indoor blower run continuously?
  On the top left hand side of the furnace is a silver box with a white push pin. Make sure this pin is not pushed in. If it is, pull it out and your blower should stop. You can also check your thermostat and make sure the fan switch is set to Auto. If the problem persists, contact your dealer.
• How important is air duct sizing? 
  Duct sizing and shape has a direct impact on how much air can actually be moved.