Lennox 80MGF fuse and pcb issue

Old 10-15-04, 10:27 PM
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Question Lennox 80MGF fuse and pcb issue

Our Lennox 80MGF furnace was not functioning. Circuit breaker was fine, but led's were not illuminated on pcb. Repairman came and found a blown fuse. It says "2". He replaced the fuse and turned on the furnace switch at which time the pcb caught on fire. He turned off the switch and declared the board bad - $418 if we buy from his company. We looked at the new fuse (which is still ok) after he left. It is a "3". Could this have caused the board to catch fire, or can one use a 3 amp in place of a 2 amp? Seems like a huge jump. Any feedback will help as we're not sure where to turn and we are freezing. Thanks!
Old 10-16-04, 11:57 AM
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Arrow My Two Cents

Hello: fixit30 Welcome to the Do It Yourself Web Site.

One would surely be inclinded to think replacing any fuse with one of higher capacity would cause major problems to electric or electronic parts. Problem is whether the new fuse installed actually cause that damage or not.

Proof of burdon. Which now lies in your hands, since the service rep has left. Seems or may be the only alternative at this time, is to call him or the company back and workout some type of compromised reduced repair costs involved. If such is possible. May be worth a try. May not work out that way.

If not, have it fixed by them anyway and absorb the costs and learn from it. Or contact another service company, pay the full price and learn from that.

At the time the incident occured was the time to begin the compromising to get board replaced for a reduced price or insist on a replacement board being installed, as a result of the new damage which occured.

That time is now long passed but a recalling back to same repair person may be worth while and well received on their part. However, if the board was damaged by that higher rated fused and the agent did not accept full responsibility at the time, may want to find another agent or service person.
Old 10-16-04, 07:18 PM
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Smile Warm again.

Thanks for the feedback. I did some research and 3 amp is a typical fuse for our control board. I ended up calling another service company, though, which stocked Lennox parts, waived the service fee, and fixed it asap. (The previous one would have had to order the control board.) The pcb caught on fire in the low voltage section where apparently two traces somehow blew. The new company agreed it was indeed a bad PCB and no one was to blame. Maybe I'll adress Lennox with the situation. Seems like a bad thing to have a board on fire at any point in your home.

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