HVAC Help

[stinger625]

Alright so i have a problem with my HVAC unit and after having 2 separate technicians come out to the house, they can't seem to figure it out and both told me to replace the whole system to fix the problem.

My thermostat in the house has a digital read out for what temperature you want it inside and then it has 2 separate switches. The first has a heat, off, cool setting and the second has either auto or on for the fan blower. If I turn the heat on Auto the burner heats out of control without ever turning on the fan and eventually the house smells like smoke. But when I turn the heat on and turn the fan to "on", the fan works fine its just inconvenient to have to hard set it; plus in the winter time at night it gets freezing in the house since there's no way to keep it warm unless i keep the heat on all night or periodically wake up to manually turn it on and off. When using the AC the auto function works fine.

Its not my limit because they have changed that like 3 times and the problem never got better. They also changed the entire control board with no change. This seems like all the electronics so I don't know what it could be. One guy took the whole unit apart and eventually pointed to something and said "your heat exchanger is cracked, you have to get a new system" when I asked him to show me where the crack was he couldn't point it out to me....mostly because nothing was cracked.

[stinger625]

Yeah thanks for nothing. I don't need you to belittle the contractors that showed up. I want to know if you've heard of this problem and what the problem is.

[aircooledtx]

**"stinger625"-* so i have a problem with my HVAC unit and after having 2 separate technicians come out to the house, they can't seem to figure it out and both told me to replace the whole system to fix the problem.

My thermostat in the house has a digital read out for what temperature you want it inside and then it has 2 separate switches. The first has a heat, off, cool setting and the second has either auto or on for the fan blower. If I turn the heat on Auto the burner heats out of control without ever turning on the fan and eventually the house smells like smoke. But when I turn the heat on and turn the fan to "on", the fan works fine its just inconvenient to have to hard set it; plus in the winter time at night it gets freezing in the house since there's no way to keep it warm unless i keep the heat on all night or periodically wake up to manually turn it on and off. When using the AC the auto function works fine.

Its not my limit because they have changed that like 3 times and the problem never got better. They also changed the entire control board with no change. This seems like all the electronics so I don't know what it could be. One guy took the whole unit apart and eventually pointed to something and said "your heat exchanger is cracked, you have to get a new system" when I asked him to show me where the crack was he couldn't point it out to me....mostly because nothing was cracked.*/-*


Would take a look at wires from furnace to Thermostat with meter, sounds like short . Not bring fan on auto in heat mode.. Best way to fix it ;is to have someone who can read a meter to check out the system.

[nomadpeo]

duke is right. you should screen your contractors because they are not qualified if they did not solve this problem in short order. it is a basic troubleshooting task. i would suggest you ask for techs to show credentials when you call for service. it may save you some time and money.