Here are your parts
Replacement parts for Roper REX3519PQ0 29" ELECTRIC DRYER | AppliancePartsPros.comSee the attachment for the wiring diagram.
You did not say what cycle type you were running.
If it was an auto cycle try a timed dry cycle.
Does the timer advance now?
If not then odds are that you have an electrical problem with the 240 volts as the heating coil and the timer run off of the 240.
Try flipping the breaker off/on slowly a couple times.
If that does nothing I would check the power.
Check the voltage at the plug
L1 to L2 should be 240 volts
L1 to Neutral and L2 to Neutral, both should be 120 volts.
If OK
Unplug the unit and check the wires at the terminal strip in the machine to make sure none are loose or burned out
If OK
Check the power at the terminal strip.
Do this with the heater off and on.
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Be careful as 240 volts is lethal !!![/COLOR]
If the timer advances in timed dry but not auto then odds are the problem is with the heater circuit. In timed dry the timer motor gets power directly from the line (240 volts) but in auto modes it gets power through the heating element when the element shuts off.
Unplug the unit and both wires to the heating coil.
Check the coil with a meter should be 8 to 12 ohms.
If open replace it.
Also check the hi-limit thermostat and thermal cut-off, both should be 0 ohms.
The reason for this is that you were having long dry times and the heating coil may have grounded out and has finally burned out.
This puts only 120 volts on the heater so you can get low heat all the time but it can also blow the high limit and/or thermal cut-off.
It would also be a good time to check/clean you vent system.
If you do not own a meter, I would suggest you purchase a one. You can get a decent digital multimeter for under $20.00. You do not need fancy though it is nice if the leads are a couple feet long.
If it saves ordering one unnecessary part it has paid for itself and you end up owning a useful tool.
Most places will not let you return electrical parts so if you order it, you own it.
A couple things to watch when measuring ohms and continuity
1. Always remove power from the machine otherwise you could blow your meter.
2. Always disconnect at least one side of any device you are checking. This eliminates the possibility of measuring an alternate/parallel circuit path.
3. When checking for closed contacts and continuity use the lowest scale (Usually 200 ohms). Then try higher scales. This scale is 0 to 200 ohms so if the device you are measuring is 300 ohms this scale would show an open circuit which it is not, you are just measuring outside the scale's dynamic range.
4. When you start always short the meter leads together. This will tell you that the meter is working and if there is any 0 offset.
There is a good STICKY at the start of this forum about it's use.