I am redoing a room and need to remove 1 cast iron radiator. It has an "in" valve on the bottom right side. I have closed this to stop water from entering radiator. The other side does not have a valve. It runs into the basement into a main pipe. It is a hot water radiator, not steam. Can I simply just close the in valve, loosen the two nuts on each side and slowly drain to remove, or will I also need to completely shut off the entire system? I have a summer/winter hookup system. It runs my heat and also hot water for everyday use. If I have to shut down the entire system I will have to time this renovation right. I have to remove some baseboard, take out some old platser wall, replace with drywall, refinish with some joint compound, and then paint the wall all prior to replacing. Once I put it back on I am assuming just the opposite of tightening the nuts, opening the valve and bleeding just that radiator, or will I need to bleed all the radiators in the house? Any and all input will help. Thanks.
By "drain to remove" you may need to drain considerable water out of the system so the water level everywhere in the system is below the level of the pipes you are about to undo. So this draining is best done down in the basement with the furnace switched off.
You can cap off the open end of the return pipe from the other side of the radiator and then you will have to refill the system before turning the furnace back on.
You will need to bleed the other radiators to get heat during the time you are doing the renovation, and drain, refill, and bleed again when putting back the radiator you removed. Additional bleedings may be needed over the next few weeks as the remaining air collects at high points (notably in radiators) little by little.
The good conscientious technician or serviceperson will carry extra oils and lubricants in case the new pump did not come with oil or the oil was accidentally spilled, so the service call can be completed without an extra visit.