Tried to install digital thermostat, now I don't have heat

[mozar]

The problem is that I have 2 black wires coming down from the top, and two white wires coming up from the bottom of the junction box. One of the white ones has black tape on it. Is that the load?
I watched this video and the top and bottom each have a white and black wire. I can't figure out what I'm supposed to do. I bought a honeywell tl820A1003.
https://www.youtube.com/watch?v=Hha1OhAlsSA

I have baseboard heat, 2 poles.

[mozar]

I looked again and it seems like all 4 wires are coming from the bottom but the black ones are threaded through the top.

[boarder42]

did you turn the power off when you did it - if not you may have blown the fuse in your furnace.

[driftwood]

Give it a year and then you can post in the "Share Your Badassity" thread about how you save so much by not having heat for a year!

[boarder42]

Give it a year and then you can post in the "Share Your Badassity" thread about how you save so much by not having heat for a year!

likely cost you more due to frozen pipes.

[ShoulderThingThatGoesUp]

Can you post a picture of the situation in the box and link to the thermostat? I couldn't find it by googling the model number.

Paging @paddedhat

[Sibley]

Honeywell has a help line. They're usually pretty good. Call them.

[mustachemountain]

the white taped black is almost certainly meant to be the black.

beyond that, you have not provided enough info to go on.
a thermostat uses a lower control voltage than your household service but you can still get a buzz off it. do you have an electric multimeter?
you say baseboard heat - electric? hot water? steam?

[ShoulderThingThatGoesUp]

THere are thermostats that can be wired in to 240-volt baseboard heaters directly: I assume OP has one.

Otherwise you need a transformer, which I set up once for this application: https://forum.mrmoneymustache.com/do-it-yourself-forum!/replacing-a-line-voltage-thermostat-with-a-standard-one-(update-solved)/?nowap

[mozar]

did you turn the power off when you did it - if not you may have blown the fuse in your furnace.

Turned off the heat and I have one of those fluke things and tested the wiring.

Give it a year and then you can post in the "Share Your Badassity" thread about how you save so much by not having heat for a year!

Lol, I actually thought about that. I probably wouldn't save much money though as it's the bedrooms where we really crank the heat up. And I would rather be a bad ass for fixing it. There's such a shortage of electricians in my area and I would like to do this for other people. Anyone know of a hobby electrician course?

@Sibley thanks for the honeywell tip

thermostat:https://www.amazon.com/s/?ie=UTF8&keywords=honeywell+tl8230a1003+thermostat&tag=googhydr-20&index=aps&hvadid=177777383747&hvpos=1t1&hvnetw=g&hvrand=11725772503157389509&hvpone=&hvptwo=&hvqmt=e&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9007751&hvtargid=kwd-4713750343&ref=pd_sl_9smya3ez5x_e

I had the exact same one before it died so I know it works. Pics attached.

[mozar]

you say baseboard heat - electric? hot water? steam?

It's electric boogie woogie woogie.

[robartsd]

You could insulate the ends of all the wires, then turn the power back on and try to determine with an non contact voltage tester which lines are hots on the supply side. For 240V there should be two supply hots and two switched hots for the load (plus any required grounding). Polarity of the hots should not matter. My best guess would be that a black and the white marked black are from the supply.

[mozar]

OK, I'll try that.