Frigidaire model # fdg648gfso does not heat all the time

While hand washing and line drying is safest, it's also costly in terms of time and effort. Unless your jeans are particularly dirty, it's best to wash them in cold water, select one of the gentler cycles, and dry them at a low temperature. Special detergents formulated to preserve dark colors really do work.
What temperature do you wash jeans? When to Use Warm Water - For man-made fibers, knits and jeans, use warm water (90°F). Most of your clothes can be washed in warm water. It offers good cleaning without significant fading or shrinking. When to Use Cold Water - For dark, bright colors that bleed or delicate fabrics, use cold water (80°F).
Wash your jeans in the sink or a tub.

1. Fill a tub with a few inches of cold or lukewarm water. Mix in a gentle, color preserving detergent.
2. Turn the jeans inside out, then lay flat in the tub. Don't bunch them or wrinkle them. Let them soak for about 45 minutes.
3. Run them under the water to rinse. Hang up to dry.
4. Can you put jeans in a tumble dryer?
   According to Good Housekeeping "All fabrics and especially jeans benefit when youtake them out of the dryer slightly damp. ... If, even after tumbling on low heat and a delicate cycle, you see lots of lint on the dryer's filter, you may want to switch to linedrying your jeans to help preserve the fabric.
   hope this helps you out.

Hi Robert Burch - From what you have described the unit could possibly have a communication problem with the control panel. However, if the unit is not producing any heat please have a professional diagnose the heating element and the blower assembly as well. Either, or, could be faulty at this time. This is not a typical DIY job so please consult a professional.

make sure all the venting is clear of build up and debris,, clogged venting will not allow the moisture to escape the dryer resulting in damp and undry clothes ,, don't forget to check the outdorr vent and clear anything built up inside of that too

The dryer might not be the problem at all. The electrical breaker might be on the way out:

The 120 motor's side is fine but the heat load side has taken a beating from the 5 thou watt 240 volt element.

this could be operator error please hear me out...... when wash bath towels you also put in wash cloths and hand towels .... there is a sensor in dryer drum shroud in front of lint filter to metal silver strips when the clothes are tumbling they sweep across this sensor telling the dryer heat to stay on and continue to dry.... if th small wash cloth sweeps it first before the bath towel then u get the same results as your describing just like if you were waqshing colors load like cotton tshirt and blue jeans the tshirt is going to dry way faster than blue jeans so if the tshirt sweeps that sensor first the dryer going to shut off we have to sort our clothes to thickness ans same size articles just try it once i bet your clothes are dry when cycle completes

Sounds like the lint tray is full or clogged

Hi, If the motor is shutting down mid cycle and can not be restarted untill cooled, the motor will need changed. It is shutting off on a safety overload. These motors cost about $145.00
Please let me know if I can assirt you further.

Vic

clean out all your vent holes,wall,dryer,lint trap,that should do it-mike

IF YOUR DRYER HEATS AT ALL, BUT WON'T DRY THE CLOTHES, 99 PERCENT OF THE TIME THERE IS A RESTRICTION IN THE AIR FLOW. PULL THE EXHAUST OFF OF THE BACK OF THE DRYER AND DRY ONE LOAD. IF IT DRIES O.K., THERE IS A RESTRICTION IN THE DUCT WORK.
CLEAN OUT THE LINT FROM THE DUCT WORK. IF THE DUCT WORK IS FLEXIBLE MATERIAL, REPLACE IT WITH RIGID 4 INCH METAL DUCT.

Check and make sure there is not lint build-up in the venting hose leading to outside. This will cause longer drying times and can be a fire hazard. Also, if you use the Aluminum venting hose instead of the white plastic it can cut up to 30 min. off your drying time. It is a lot safer then the white venting hose which can also be a fire hazard. Make sure all the lint is cleaned out from the inside of the dryer where the venting hose is connected. It could be a clog there. This sounds more like the problem since the clothes are actually drying but it could be a partially burnt out heating element. Good Luck.