Recently I purchased a different thermostat and installed it by myself. When the new one was installed, it did not work. I thought it was broken and placed the previous thermostat back on.
The previous one does not work either. It was perfectly working yesterday before removing it.

Now I tried to reset the system with blaker on/off. Furnace on/off.
The thermostat screen is blank and no sign of power. Furnace is not working at all.

I am thinking this may be related to blown fuse? I may have touched two wires together by accident during the replacement process?

The one I want to put back on (the previous one) is Honeywell Peaksaver thermostat. Does this model have a fuse?

 

Welcome to the forums.

There are no fuses in the thermostats. The fuse would be in the furnace.

How many wires are on the thermostat ?
Was there a C connection/wire involved ?

 

Thanks for reply.
Yes there is C connection. Total 4 wires.
K W C R/Rc (connected by jumper)

 

You're close...... W, C, R/Rc are valid terminals.
Not sure what K is. If you have A/C.... maybe it's a Y ?

Ok. Since you lost power and you do have a C involved..... hopefully you just lost a fuse.

Go to your furnace. Remove the lower blower door. You should see a control board there.
It should have a fuse on it. If you can't see a fuse post me a picture of the board or it's part number. http://www.doityourself.com/forum/el...-pictures.html

 

I found the 3A fuse. Thank you so much! You saved us from cold...we were freezing in -12 outside temp...

 

Those are basically automotive fuses. Could probably steal one from your car if you don't any handy.

 

Thanks we checked our car but it uses a different type of fuse.
Unfortunately it was already past 11pm and all the stores were closed..but will be able to get one tomorrow

Thanks again for saving us!

 

What, you don't have an all night Auto Zone?