25 year old whirlpool furnace model# NUGG125AHOL

[jayray]

       A relative has a 25 year old whirlpool furnace MODEL# NUGG125AHOL  that wont shut down at all. They replaced the T-STAT (GOLD,ROUND HONEYWELL WITH HEAT /AC) ONLY 4 WIRES. First I tried to turn dial below temp. to see if this would shut it down using the mercury switch but it still runs past goal temp. I then used the off switch and it shut off. the wires inside are hooked up properly and the anticipator is set correctly .6 amp. could it be limit control or gas valve, they said condensate was leaking onto it but was repaired. pilot was off when I got there had no problem lighting it. In short, she must manually turn furnace on and off at T-STAT to run furnace. I will respond with any questions. thanx again.   

[RegUS_PatOff]

was it OK  BEFORE they replaced the Tstat ?

wired correctly ?

even so, try dis-connecting it on the furnace side.

 

[jahjahbinks]

are you stating that the only way you can shut it off is to turn the tstat down ? or kill the power?

[jayray]

if you turn the tstat switch to off position it shuts down furnace.

[jayray]

they replaced t-stat because they thought it would solve same problem. it didnt.

[jahjahbinks]

then i would replace the tstat what you have is a honeywell t78f tstat this has 2 parts u have the tstat then on the wall u have the subbase this has the switches on it , because you can operate the furnace from the tstat then that says you don`t have a problem with furnace just a problem controling the operation from the tstat i would statr by replacing just the t87f tstat HEAT / COOL very easy to replace if your problem continues then you will need to replace the subbase . but just for safe keeping i would also remove the old tstat (only) and see iff the unit still runs if so change the subbase if not replace the tstat , but keep in mind if the red and the white wires touch at any point this will call for heat .

 

hope this helps

[jayray]

Iam going to replace the sub-base and see what happens. thanx. 

[jahjahbinks]

[user=30056]jayray[/user] wrote:

Iam going to replace the sub-base and see what happens. thanx. 

my suggestion is to first remove the tstat then check operation