Engine temp not reaching normal operating temp

Engine running cold.mean open.engine overheating ,stack closed.

If you know for sure the thermostat is working, it could be low on coolant and has air pockets in the system. Only one radiator hose should be warm until the engine reaches normal temp, and both heater hoses should be very warm.

That is pretty much normal, the heater blower fan acts like the radiator does and helps cool the water passing through it by extracting the heat from it. then once the car inside temp warms up it goes back to normal. Nothing to worry about.

Air can be purged. While your engine is cool remove radiator and reservoir caps. Place funnel in radiator. Turn heat to the highest position and start vehicle. Add coolant to radiator as needed while vehicle warms up. You should see bubbles coming out of radiator. Fill reservoir to between cold and hot fill lines. Replace caps when bubbling stops but before coolant temperature reaches normal operating temperature. Never remove the radiator cap until engine has fully cooled down.

Replace tempature sensor

If the check engine light is not on, I would want to check the computer with a scanner to see what the temp sensor is telling the computer the coolant temp is. The problem could be in the computer or the fan relay.

sounds like a fuel problem , water in gas , ......

1st check the coolant level to make sure it's ok, low level can result in insufficient heat. What is going on with the engine temp? Is it running on the 'cool' side or normal range, in the normal zone, or running hot? If it is on the low side of normal, you may need a new thermostat. If the thermostat sticks open, the engine won't reach operating temp, and you will have minimal heat.

I suspect you are right with the thermostat angle.

The new thermostats are the opposite to the old ones that used to cook the motor when they failed.
The new ones run too cold in case of failure and also up the fuel consumption because the computer gives a cold motor more fuel than a hot one.

The water temp sensor is a switch that closes the circuit when the temp reaches a certain level and that switch sends power to the fans. Either your water temp sensor is faulty (always on) or the wiring from the sensor is shorted out. 
The easiest fix would be to replace the temp sensor. They are cheap, and replacing it will likely fix the problem. Your local parts store can get you one and show you where it is located on your car. 
If it doesn't fix your issue, at least you'll have eliminated that from the problem and can search for the short in the wiring. 
If you know basic electrics a simple auto circuit tester (cheap at any auto parts store) or multimeter will help you trace the short. If you're competent with electronics, you can always wire the sensor to the fan independently of the car's wiring harness to workaround the short. Be sure though that you have a workshop manual with a wiring diagram and that you make the correct connections to the switch, fan and the car's 12V power.
I'll bet that replacing the sensor will take care of it though.
Hope this helps.