Gas and Oil Home Heating Furnaces - Is it necessary to replace complete furnace

Just had a serviceman come by to service my (Carrier) Gas Fired Forced Air Furnace (Model# 58pb075111c, Serial #w697354, 75,000BTU). Lots of rust from heat exchangers covered burners. Said one of the three heat exchanger's flue had a hole in it and it was unsafe to operate. Said either replace heat exchangers or replace complete furnace and difference in cost was only $200-$300 difference. I have no experience with furnaces. Does this sound like a sound diagnosis? Is it necessary or a good idea to replace complete furnace because of hole in heat exchanger? Furnace is most likely as old as house (16 years). Please reply. Thanks:confused:

i would agree with the technician that was out there. if in fact the heat exchanger is cracked, and the unit 16 yrs old, replacement with a new unit will give you the reliability and efficiency you need. get a second opinion, though, as well as other prices.

Hello Big Ron

Hvac4u is correct in all aspects of the reply posting. Fireboxes that are cracked or have holes in them are hazardous. Get several opinons, estimates and possibly a smoke test done on the firebox, if this practice is done by heating agents in your area.

The reason a crack in the firebox is dangerous is 2 fold:

First, fumes produced by the combustion of gas produces several unhealthy products. One of them is carbon monoxides. The fumes will pass through the hole and or crack and enter the living area.

Secondly, the air from the fan, passing over the firebox, will effect the flames {fans the flames} which in turn disrupts the natural burning process. This action then produces extremely high levels of carbon monoxides.

Heat exchangers {Fireboxes} are not repairable, only replaceable. However, furnaces over 10 or so years old, replacing them may not be cost effective.

Suggestions:
Read the manufacturers online web site for further information, which may be available online.

Check the ARCHIVES, within this forum, for other postings on this topic and the replies offered.

Regards & Good Luck
Gas Appliances Forum Moderator
Tom_Bart...........Fast, Fair, Friendly & Highly Efficient.....:)
Energy Conservation Consultant & Natural Gas Appliance Problem Diagnostics Technician.

Although I have spent many years in the gas appliance industry, some appliance diagnostic information provided is exclusively from memory....Devoid of any "Pre-Senior Moments" of course........:D

You were giving great info.The only thing I'll add is---your heatx is,16 yo as well as the rest of the components.One service call to replace the fan motor or gas valve will eat the money you saved by just replacing the heatx.PDF