Home Improvement → Re: [HVAC] hooked up wrong thermostat/blew something up

Any chance that you know what a paragraph is and you could start using them? I have tried to read your posts and it is next to impossible. Then you appear to accuse those trying to help you that they are the problem. Please try to organize your thoughts, use paragraphs, and generally make it easy for us to go through the info you are trying to communicate with us in an organized manner.

Please don't be snarky. The mods don't like that.

Maybe the fuse on his enter key is broken, too.

Personally, I would like to know how a thermostat was not the right one. Every thermostat that I have seen has some basic level of compatibility. You might need to flip a switch for gas/electric and some might not support dual stage blowers, but is there really something to look for when replacing a thermostat?

My biggest concern when replacing a thermostat is making sure that I don't lose the wires back into the wall cavity.

Assuming his first purchase was a RTHL111B ( could find no listing for a RTHL1118) , the only difference between it and a RTH3100C is that the correct one is rated for a heat pump with AUX heat . The 118 is rated for a heat pump without AUX heat .

Since he posted that his air handler had 3 fuses in the disconnect box , sounds like he had AUX heat .

Of course , even with the complete and accurate model numbers , and having checked on line to see just what you have , you end up going to buy the new one and are faced with this »yourhome.honeywell.com/h ··· mostats/ ! And that is just one brand
Add to that the fact that a lot of the packaging does not show all the details that the inner paperwork shows , I am not surprised that people get the wrong one .

The "wrong" thermostat would have been missing a terminal to hook up the wire to control the aux heat, right? It still would not have caused a blown fuse.