thermostat honeywell

Hello, I'm new to this forum and have made this account to ask some questions. I really hope someone can help me. To cut a long story short, I hired some plumbers to install a new Vaillant Ecotec Pro 24 boiler and they told me that they can do all of the relevant electrical wiring themselves...

So, trying to replace my old th8321u1006 with a 9000 series Honeywell. Of course, this supposedly simple project is anything but. Could you all give some advice? What is wrong? That interesting blue wire was not connected to anything on either... Starting with the old thermostat, then the...

I have a Bryant Plus 90 (installed in 1995) gas furnace and heat pump/ac unit to which I am trying to add a Honeywell Lyric T5 Thermostat. I am having trouble Wiring it because the original thermostat (Bryant brand) has separate O and B terminals while the new one has a single O/B terminal...

The buttons to change the temp on my thermostat stopped working, but it still functioned properly. My brother gave me one. I wired it just like the old one, but it blew warm air. I reinstalled the old one...cold air, but couldn't adjust temp. I bought a new one and wired it exactly like the...

Currently my home uses two Honeywell Chronotherm IV Plus thermostats (see the attached picture). I would like to replace them with smart thermostats which I can control anywhere on this planet via a smart phone or a computer. Could you make some recommendations? I checked honeywell website at...

Was demoing out a damaged hospital wing and snagged a new honeywell simple digital thermostat thinking I could easily swap it with mine at home (buttons no longer work to adjust temp) turns out I grabbed a more complicated wiring version than mine and need help figuring this one out. Old Unit...

I'm thinking about buying a new Honeywell RTH7500D thermostat for my Lennox heating/cooling system in my home. I like the idea that it will "auto change from heat to cool". It also has a 7-day programmable feature that I like. The problem that I am trying to solve is the west wall of the house...

My Dad purchased two Honeywell RTH2410 programmable thermostats and I'm having trouble installing the one for the second floor. The first floor has a furnace and installed without a hitch, but the second floor has a boiler and there are extra wires. The wires from the wall are: Black Blue Y R G...