Turning Off Radiators? Help or Hurt?

Julian Francis

Greetings!

I have a one-pipe steam system in my 130 year old Victorian home. I have 16 cast iron radiators throughout my house on three floors. I currently only have 12 radiators turned on.

Will that hurt or help my system? Should I have all 16 radiators on?

Thanks in advance for any helpful commentary.

Geno_15

25%

If you have 16 and are running 12 you have cut the system by 25%. This figure is assuming all the radiators are the same size. Is this feasible? Depends, is the boiler now short cycling? is it surging? are the radiators that were shut off in closed rooms and in danger of freezing? with 1 pipe if all of the water drained out before you closed the valves you may be ok.

You need a professional to look at this and if it will work they should cut your firing rate down to match the new load, by 25%. Steam likes to go slow and even with 25% shut off the system may surge/short cycle/or both. Then do you get h/w off the boiler and if so will cutting the firing rate 25% still give you plenty of h/w??

gehring_3

Keep all 16 on. The boiler is rated to produce X amount of BTU per hour whether the radiators are all on or not, so you are not saving anything by closing off 4 of them. In fact, the system may be out of balance or short-cycle on pressure with the redution in radiation as it would then behave as if it is oversized for the connected load. Turn them all on and leave them on. (That is assuming the boiler was properly sized to the 16 in the first place)