|
Posted by Casey on January 22, 2007, 6:46 pm
Thanks for the reply.
Yeah, those two resistors do look like they have been overheated.
I cleaned the ignitor and flame sensor and where they contact the mount
yesterday (with steel wool and wire brush). I thought that might have done
the trick because the heat worked all day yesterday afterwards and this
morning (which was very rare beforehand). However, it was locked out when I
got home today. :(
>
>>I have a Carrier 48SS-036100331-- (about 11 years old) and my house is
>>approx 1750sq ft. The heat works fine when the outside temp. isn't too
>>cold
>>(ex. greater than 50 degreesF). However, when it is colder outside, the
>>unit
>>frequently locks out. The exhaust fan continues to run, but the burner
>>isn't
>>lit. I had to have my heat exchanger replaced last season. I vaguely
>>remember the technician saying it was likely there wasn't enough airflow,
>>so
>>the exchanger was getting too hot which decreased it's lifespan. This made
>>me suspect that the limit switch was tripping. However, the led on the
>>controller board blinks 8 times when it's locked out, which corresponds to
>>"internal control fault" according to the schematic. I have opened all my
>>dampers to maximize airflow. When I flip the breaker off then on again to
>>the unit, the burner will light up again and will work for awhile and then
>>lockout again if it is cold outside. Here are pictures:
>>
>>http://www.commercialinstallations.com/Misc/heat.htm
>>
>>Any ideas? "Internal control fault" sounds like the controller board, but
>>why would it work except when it gets cold out? What is the best way to
>>troubleshoot "internal control fault" error?
>>
>>Thanks,
>>Casey
>>
>
>
> look in the middle of the circuit board, see the two big square white
> resistors and the two resistors immediately above them? One looks
> like its been over heating....also the mounting holes/slots in the
> ignitor assembly.....sand paper the metal around those mounting
> locations as well as their corresponding mating surfaces where they
> mount. you need a good grounding connection there...
>
> too bad when they replaced your heat exchanger they didnt also replace
> the totall rusted out inducer housing. Inside that inducer housing is
> a totally rusted inducer blower wheel. the wheel should have been
> replaced as well, as they tend to disentegrate
>
> also, check for tightness on all stake on connectors and the edge
> connector on the ckt board. those units are notorious for
> over-firing. be sure to check and set the pressure at the gas valve.
> your service tech should have de-rated the burners if its overfiring
>
> see that round black gizmo with wires coming out of it at the back of
> the inducer motor? thats the Hall-Effect sensor, a total piece of
> shit. It tells the control board the inducer motor is running and
> its ok to open the gas valve and spark the ignitor. It is a piss-poor
> design though, as the inducer motor can be spinning a totally rusted
> out inducer wheel. So when the gas ignites, you get major flame
> roll-out, which usually burns all the wiring up. Did I mention I LOVE
> CARRIER??
>
> finally, take a shop vac to the crap in the bottom of the burner
> compartment. cleanliness is next to godliness.
>
> ps- error code 8 is carrier's way of saying.....get ready to spend
> the big bucks....
| 
Yahoo! 
Google 
Windows Live 
del.icio.us 
digg 
Netscape 
XML Sitemap