Replacing a cracked heat exchanger is no easy task, especially in a 10-ton package unit. Markus and Tyler work in the light of the afternoon to carefully remove a large tonnage heat exchanger with several holes in it.
What are the symptoms of a cracked heat exchanger?
Your furnace won’t come on.
A heat exchanger crack in a residential furnace large enough to cause trouble usually upsets a steady flame or causes the burner flames to roll out the front of the burner openings. This can cause a fire or burned wiring and should trip the “rollout switches”, which are temperature sensors located near the front and above the burners.
If the crack or split is really big, it may keep a burner from lighting correctly (or blow it out) and cause a delayed or concussive ignition. In really bad cases the concussive can blow the access panels off the front of the furnace. On older furnaces with standing pilots, a big crack might cause the pilot flame to be blown out, which turns into a no-heat situation.