Hi

I have a furnace that trip at 170 degree celcius..When thi shappen the room in which the thermostat is ,is only 65.what is the problem?The furnace works for 10-14 minutes and then the high limit switch or rull out swtich trip.
Do you know what the cause is?

Thanks

Make sure all registers are open.
Check and replace dirty air filter
Make sure return air is open with no blockages.
It is possible the limit switch is defective or out of calibration and needs to be replaced.

some of the registeres were closed .I opened all of them.still tripping.The thing is the temperature of the supply duck is 170 F.so the high limit is doing it's job properly.Do you think there might be a problem with the manifold presure(I did not tested it!)

Other possibilities: clogged A/C coil (if present), duct restriction (loose internal insulation, if present), blower not running properly.