New 13 SEER Trane with an Old A/C Compressor

[gnd]

I recently bot a condo with a bad furnace. I had it replaced with a new 2006 Trane. I did not replace the old A/C Compressor as it was working fine. After about a week, the AC stopped working. My home warranty provider sent a tech out to inspect the AC. He and the home warranty provider say that the new furnace is a 13 SEER and it will not work properly with my old A/C (6 or 8 SEER) without a hard start relay kit. This was not installed. Therefore, they are denying my claim on the busted AC. Should the furnace installer have known about the hard start relay kit and, therefore, be liable for the repairs? I'm clueless about this stuff and, unfortunately, must educate myself quickly. Thanks.

[BaldLoonie]

Yes. If you are talking an electric furnace/air handler like the 2TGB or 2TEC, it has a non bleed expansion valve coil which will not work with old A/C units with recip compressors. He does need to put a full hard start kit, not a superboost, on the outdoor unit to get it to start. He should have added it to his bid when he quoted you the new indoor unit.

[the cleanup crew]

We have had numerous problems this year with the installation of new 13 seer evaporator coils. Some companies in our area have been slapping in the new coils without installing the start assist kits. If you have recip compressor and a txv installed in your evaporator coil you must have the start assist kitinstalled on the condensing unit for the proper operation of the compressor. As Mr. Loonie explained above you need a full start kit installed which includes a potential relay and a start capacitor. I would without a doubt go back on the installers.
GOOD LUCK

[gnd]

Thanks for the info. One follow up question, if I may. Would the lack of the hard start kit burn the compressor up completely?

The installer came back and installed the kit but the compressor still fails to start. The unit was without this necessary kit for about two weeks in late August (i.e. the a/c was working hard). The installer claims the compressor failure is due to age of the unit (yes it is older than its life expectancy) but it was working perfectly prior to the furnace installation. Any thoughts?

Thanks,

[Fatty]

everything works until it breaks.
Most annoying thing a homeowner can say is "It was working fine up until today"....No kidding? Really? I thought most people call us before it breaks so we can fix it........ You got a furnace and coil installed by someone who didn't install it correctly. Make him fix it....

[Freezeking2000]

Possibly it contributed to it's failure, but most likely it was ready to die. It may have cycled on the overload from not starting just once to many times.

[the cleanup crew]

I would lean to the idea of the compressor failing due to the lack of the start assist kit. The reason for this is because the compressor will run hot without the kit. One of the most common symptons to the unit not haveing the kit installedis the unit will cool for a period of time then stop, then come back on if it was allowed to cool down. The compressor is actually running hot and the internal overload is opening. Which if the unit is turned off for a period of time and then is turned back on the compressor will come back and begin to cool. But, the system is already past its due date and now it is running hot for a long period of time opening the internal overload. Most likely stuck overload or the windings. This in my opinion falls back on lack of knowledge (happens to everyone) about the eqipment. Good luck again.