Here are your parts
Replacement parts for WHIRLPOOL REX6634RQ1 | AppliancePartsPros.com

See Item 17 in the Bulkhead section

Here is the wiring diagram
http://www.servicematters.com/d...0Sheet%20-%208576793.pdf

I am assuming that the drum rotates and you just do not get heat!!
NOTE: Be sure to unplug the unit when opening it up and working on it, 240 volts is lethal!!!

Does the timer advance in timed dry mode?
Both the timer and the heater require 240 volts.
If not try turning the breaker off/on slowly a couple times. Sometimes you can loose half the line without actually tripping the breaker. Better yet measure it with a meter.

If the heater measures OK (10 ohms approximately) the next possible cause is the thermal cutout Item 6 in the Bulkhead section (0 ohms at room temperature)

If the thermal cutoff is blown be sure to give the interior including the blower wheel a good cleaning. Also clean/check your 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.

There is a good STICKY at the start of this forum about it's use.