I replace 3 conventional bi-metal thermostats by 3 programmables NOMA thermostats
Model htm611A n° 09014026892
Model htm611A n° 09014026894
Model htm611A n° 09014026896

After 24 h the display went off and the heater run constantly.

I install 5 others thermostats the same day. They run fine.

Is there any known problem about this thermostats?