Draining and moving a radiator?

Michael Michalski

I need to move a old style radiator to replaster the wall behind it. I just moved into this house and this is my use of hot water heat. I have been told I need to drain the whole system to remove the single radiator. I have an idea how this is done but I cannot find any resources on draining the furnace and do not want to damage anthing. Are there any resources? Is this a difficult job? Some people say it is easy others say I should not mess with it. I need some advice and/or instruction.....mike

heretic

Pretty easy

Hot water, not steam, right?

You basically need to drain every pipe and rad that is at a higher altitude then the base of your subject radiator. These instructions assume you have a typical fill valve and such.

1) Shut off the boiler (using switch at boiler) for safety.
2) Shut off fresh water supply to boiler.
3) Isolate other zones, if it is piped in a way that allows this.
4) Attach a hose to the boiler drain, and run it to a floor drain or sump pit (assuming boiler is in basement). If you have no floor drain, you will need to rig up a small pump.
5) Open drain.
6) Open the bleeder valve on the highest radiator (on same zone). Drain until subject radiator is dry. You can open fill valves an a couple of the highest radiators to speed things up.

Breaking the connections at the rad may be the harder part. You may need a bigger wrench.

Refilling:
1) Close all bleeder valves
2) Turn on fresh water supply. Pressure gauge should rise (12-15psi typical)
3) Bleed each radiator in sequence starting with the one that is closest to the boiler, and ending with the one that is furthest from the boiler.
4) Turn on boiler, and re-bleed every radiator again after a day or so of operation.

Michael Michalski

yes hot water

Thank you for the info. I have two good size pipe wrenches. Can the system be overfilled? Sould I drain out the tank above the boiler as well? How long does it take for the water to leave?

heretic

Cannot overfill

The system could theoretically be overfilled, but the pressure is generally regulated to a max of 12-15psi if you have a standard auto-fill valve that is working properly.

Presuming the tank above the boiler is a typical bladder-type expansion tank, nothing special needs to be done with it. If you have an old style 'plain steel expansion tank', I am not familiar enough with these to offer up any advice.