It came to our attention about a month ago that we only had 3 of the 4 elements (coils) plugged in properly on our 80 amp furnace. So when the repair man came by to fix our furnace, he mentionned it and reconnected the 4th element but since then every time the furnace starts to heat the house it tripps the breaker in the fuse box. Now when the repair man came back, he said that the breaker in the fuse box was not strong enough to handle the load. So he is basically telling me that I need to get an electrician in here to change both the wireing from the furnace to the fuse box and also the breaker in the fuse box, right now the breaker we have at the moment is a double 70amp breaker. How can I be sure that the breaker is not big enough to handle the load.

An Ampprobe will tell actual Amps.
Wonder if last element was wired correctly?
Does Nameplate give any info?
80 Amps seems large, Is this a Very Large or Very Cold House?
The Breaker should not be Larger than the wire it Protects,
Are they #4's or Larger?

Also, if wires are loose on the Breaker or if the Buss wher the Breaker plugs onto is Burnt or coroded, it can trip at lower amps.
Loose connections generate Heat.

Also, if wires are loose on the Breaker or if the Buss wher the Breaker plugs onto is Burnt or coroded, it can trip at lower amps.
Loose connections generate Heat.

We just had the breaker changed but he replaced the 70 amp breaker with a new 70 amp breaker, then the repair man to us that the breaker was to small to handle the load

Did the furnace work fine with 3 of the heaters? You may not need to change all the wire inless you was way short on heat.

did the furnace work fine with 3 of the heaters? you may not need to change all the wire inless you was way short on heat.

The house is 5 years old and everything has worked fine until 2 months ago when the furnace caught on fire, that's when the repair man came by and notice that one of the elements was not connected and reconncected it and that's when the situation with the breaker started. The house heats up much faster with all 4 elements. If the wirering was not done properly in the first place I will try to get the electrician that wired the furnace to come basck and do it properly and if he is not around I will get another electrician.

Did they say what the cause of the fire was? Is your unit capable of have 2 wires? Some units you can run to smaller wires, like 2 40 amp breakers. Some units you can not do it that way.

did they say what the cause of the fire was?? is your unit capable of have 2 wires? some units you can run to smaller wires, like 2 40 amp breakers. some units you can not do it that way.

They did not give a reason they just came and fixed it and that's when they noticed that one of the four elements was not connected.

You may have a short with your Heat strip to Ground if wiring had melted and not corrected. You could look for resistance between the heat strip and ground to determine if you have a short, should be no resistance.

You may have a short with your Heat strip to Ground if wiring had melted and not corrected. You could look for resistance between the the heat strip and ground to determine if you have a short, should be no resistance.

I am not quite sure what that means but the repairman assured me that everything was OK and he is the one that said that my wirering and breaker should be bigger than 70 amp.