Do you have vents you can open and close? If so, check that the vent was accidentally closed. I hope it's something as simple as that.

Alas, no, nothing like that. It's a hot water baseboard system so there are two five or six foot long units in the room, and there's no heat coming out of either of them anywhere.

Oh, that really sucks in this weather. Personally, I like a cold room - Mr. V and I shut the heat in our room just for that reason. I wish I had words of wisdom for you. My brother the plumber said it could be a zone problem, or perhaps an air bubble blocking the hot air from getting into your bedroom. I'm not sure how to fix either - he said it all depends on how your system is set up. (I didn't know there were different hot water baseboard systems).

Arrgh, I feel for you - I had this problem with my central heating system, the big radiator in the living room wasn't working. With UK hot water central heating, we don't have baseboard heaters (I wish we did). We have big, cumbersome wall-mounted radiators, but they all have an inlet and outlet valve so the radiator can be isolated from the system if necessary (comes in useful if you need to wallpaper behind it or something, you don't have to drain down the entire system).

Turned out the inlet valve on mine was stuck, probably gummed up with cat fur detritus. A little WD40 did the trick. Is it possible there's some kind of valve on yours that's stuck?

It's certainly possible, but I'm not up to looking into it tonight. I resorted to a space heater for now. Something gummed up by cat hair would definitely not surprise me -- it's everywhere around here.

Rats might have eaten your ducting.

On a hot water system???

I failed reading comprehension.

Maybe your radiators are full of air and need to be bled? I'm not sure about more modern baseboard ones but our giant cast iron onces need to be bled once a year.

I have wall mounted radiators like Jan's, but from what I see about baseboard systems, it seems like in order of pain-in-the-ass magnitude and likelihood:

1) vacuum/dust the underside of the "fins" (this is the part that I don't really visualize because our wall-mounted ones don't have this feature... but I suppose it will be apparent to you). See here, and number 6 of baseboard heating blues.

2) bleed the line (number 4 of baseboard heating blues, above). Now this one, I know... it used to take us an hour to get the whole system bled and working with our old radiators... the ones in this house don't have this trouble. yay!

3) if the bedroom is that the last stop on the loop, the water may just not be hot enough any more, and you might need to adjust the flow control rate as described in the fifth paragraph of baseboard heating blues.

Aside from these efforts, probably anything else will need to be addressed by a plumber... Possible problems might be a leak; sediment/build up/junk in the line; maybe a pressure problem if your bedroom is on an upper level?

I hope we'll hear from someone who has this same sort of system and can give better first-hand advice.

In the meantime, allow me to amuse you. Please check out this DIY forum post, especially the initial post and the second comment. Has me incurably giggling this morning... but they seem to be different people; is this adamantly possible?