We have hot water baseboard radiation heat. How is it possible that the first room the hot water is supposed to heat is cold and the second and fourth room are to hot and the third and fifth rooms are just right?
Most hot water baseboard is not radiant to any significant extent - it's a convector (air heater) and most can be adjusted to flow more or less air (resulting in more or less heat) by adjusting "flaps" on the baseboard shell. They can also (especially old setups in place for a long time) be impacted by buildups of hair, lint, dirt, dust-bunnies etc. that block the flow of air, so opening up the shell and vacuuming and/or blowing out decades of detritus can make a big difference.
I would expect the heat of the water in the radiators to drop a little bit as it travels along the loop but there are other considerations to how warm or cold a room is:
- how many feet of radiator are there in the rooms? More radiator length will mean more heat is delivered in that room.
- how many windows/doors in the rooms? Are any of the rooms drafty? Do you have a fireplace that is losing heat? If the rooms have very different heat loss situations that could explain it.
- is the heat well-distributed in the rooms? Maybe there are hot spots and cold spots that could be solved with a small fan.
- is there any furniture blocking the radiators? A large couch pushed up against a radiator could block a substantial amount of heat.
If the entire floor is one loop there may not be an easy solution but you could talk to a plumber about adding/removing some sections of radiator and/or installing a bypass on some of them.