What size heater do I need for my home?

Here is the easiest way to find out the size or capacity of your existing heating system:

• Go to your indoor unit (furnace) that looks like this:
  
• Find and take a picture of the label that looks like this:
  
• Look for Input BTU number — that is heating capacity of your system (in the example above it is 70,000 BTU).
• If you do not see Input BTU number, find one of the following codes in the model number — it will tell you what the capacity is:
  

  If you see this…	…then your capacity is this
  040 or 40	40,000 BTU
  045 or 45	45,000 BTU
  054 or 54	54,000 BTU
  060 or 60	60,000 BTU
  070 or 70	70,000 BTU
  072 or 72	72,000 BTU
  075 or 75	75,000 BTU
  080 or 80	80,000 BTU
  090 or 90	90,000 BTU
  100	100,000 BTU
  120	120,000 BTU