How do I remove a radiator for cleaning/painting?

Dave Belisle

Sounds like everyone here has you covered. You should be
able to do the job youself, just think it out a little, as the old paint is lead based.
You will want to where breathing protection and
put a little thought into where the paint chips are going. You don't want them all over your yard or your house.

I installed three old radiators in my house years ago.
I cleaned them up and painted them with a off white enamel paint from spray cans that came right off the WalMart self.
Not even high temp.

They look as good now as the day I painted them.

Good luck

Dave the Plumber TL DMS

BP&H

Rich Lytle

How do I remove this radiator for cleaning & painting?

I’d like to remove this radiator (see pictures below) from my bathroom to be cleaned and repainted. It probably has not been removed since it was installed about 100 years ago. Is this a do-it-myself job? Any tips on what I would need to do? Is it just a matter of loosening up the couplings at the base of the radiator? How do I drain the water first? I assume I would have to shut off the main inlet valve, open up the bleeder on the radiator, and then open up the drain at the boiler in the basement. Is that correct?

Next, what’s the best way to get this cleaned up? Sandblasting? Any recommendations or ideas on how to find someone to do that?

Any tips on painting? Do I need to use a primer first? Special type of paint? Can I just use spray paint? I’ve seen “high heat” spray paint at the hardware store for things like stoves and radiators. But the radiator probably doesn’t ever get over 140 degrees or so.

Finally, how do I get it hooked back up? Just put it back into place and tighten the couplings? How tight—as tight as I can get them? Do I need to coat the threads with anything? Then do I just turn the water back on and bleed the air?

Sorry for so many questions. If I am going through the trouble of doing this, I want to make sure I do it right. Thanks.

Rich Lytle

How do I remove this radiator for cleaning & painting?

I’d like to remove this radiator (see pictures below) from my bathroom to be cleaned and repainted. It probably has not been removed since it was installed about 100 years ago. Is this a do-it-myself job? Any tips on what I would need to do? Is it just a matter of loosening up the couplings at the base of the radiator? How do I drain the water first? I assume I would have to shut off the main inlet valve, open up the bleeder on the radiator, and then open up the drain at the boiler in the basement. Is that correct?

Next, what’s the best way to get this cleaned up? Sandblasting? Any recommendations or ideas on how to find someone to do that?

Any tips on painting? Do I need to use a primer first? Special type of paint? Can I just use spray paint? I’ve seen “high heat” spray paint at the hardware store for things like stoves and radiators. But the radiator probably doesn’t ever get over 140 degrees or so.

Finally, how do I get it hooked back up? Just put it back into place and tighten the couplings? How tight—as tight as I can get them? Do I need to coat the threads with anything? Then do I just turn the water back on and bleed the air?

Sorry for so many questions. If I am going through the trouble of doing this, I want to make sure I do it right. Thanks in advance!

Bob Harper

DIY?

Rich, I'm not a Wet Head (boiler tech) but let me speak for them:

This is NOT a DIY job. You should hire a boiler tech to not only remove these radiators but consult with you on cleaning, painting, etc. then to re-install. More importantly, how long has it been since you paid a professional to do a thorough cleaning, inspection, and testing of your system including the chimney? Might want to consider more important things than the appearance of a radiator first.

Just my opinion.

Rich Lytle

Thanks

Thanks Bob. I had a new boiler professionally installed three seasons ago. I had it checked out/tuned up last October.

Important things have been done; I'm ready to move onto the less-important things.

Mike T., Swampeast MO

Well, some is definitely a DIY-sort of job.

Usually the worst part is properly re-filling the system--draining is comparatively easy.

The system will have to be drained to a level BELOW the radiator you want to remove. Connect hose to the boiler drain, open valve and immediately open the bleeders on the highest rads. Then open bleeders on short rads on the same floor until ALL on the highest floor are open.

Then go to the next floor down and open a bleeder on the highest rad. If you get water, close. Continue this way until the bleeder sucks air. Then close your drain valve (provided the rad you want to remove is on the floor above.)

Rads attach with brass unions that do not tend to "freeze" even if untouched for many decades. The "captive nut" of the union stays on the radiator side. Use a pipe wrench to open the union. You'll be pulling up with the wrench on the right-side connection, pushing down with the wrench on the left. Once both unions are free, try pushing the rad or piping to one side or the other. You usually only need about ½" of "wiggle room" to free up one side, rotate the radiator and then pull away from the second. If no wiggle room, you'll have to turn the valve or the union elbow slightly away from the wall to free the joint. I prefer to loosen slightly, so that means turning the left-hand connection. USE TWO PIPE WRENCHES IN OPPOSITION TO ONE ANOTHER FOR THIS OPERATION!!!! One wrench on the valve/union elbow, the other on the pipe below. Use only one wrench and you risk breaking a joint further down the line--something you DO NOT WANT TO HAPPEN!!!

Sandblasting is probably the most effective way to strip a radiator. If sandblasted, you MUST prime almost immediately or the surface will begin to rust. Use ONLY oil-based paint for priming bare iron! Top coat can be either oil or latex.

I've found that pressure washing with a zero-degree nozzle works well for stripping rads. This usually takes things down to the original (and well-adhered) primer or bronzing. Since rads are rather difficult to clean, later coats are frequently poorly adhered and the pressure washer (again a zero-degree nozzle) will remove them rapidly and easily.

They can also be soaked in paint stripper (usually a home-made lye mix) as commercial strippers are too expensive. Use a heavy-plastic lined wooden box that can be filled at least half the width of the rad. I've never done this method, and really don't want to... I do know however that it works quite effectively.

All holes in the rad MUST be plugged if sandblasting or chemically stripping! No need if pressure washing. When removed, it's also good to flush the radiators several times with clean water.

To reinstall, just reverse the steps. Unions seal by metal-to-metal contact and brass is rather soft. Do not over-tighten. In my mind it's better to have them a bit too loose (with a little leak) and then tighten, than to risk over-tightening. Before assembling, wipe the union mating surfaces with a clean rag to remove any dirt, etc!

To refill: If this was on an upper floor and you didn't have to completely drain, it's mainly a job of opening the fill valve and removing the air via the bleeders. Often (but not always) there's a pressure-limiting fill device that [should] stop filling when the system is properly pressurized (usually 12 psi) for a 1-3 story system. If not, you have to pay VERY careful attention when filling to get the right pressure. Once the final bleeder is closed, the pressure will ZOOM up. If you don't turn off the fill in time, you'll "pop" the temperature and pressure safety device on the boiler and have a BIG mess!

If you've drained completely, I'd really suggesting calling in a pro as there can be MANY variables. Good if that pro is willing to let you watch and question, but do expect to pay more for the experience... Personally, I think every homeowner should know how to properly drain and fill their own system.

Rich Lytle

Thanks

Thanks Mike! I appreciate the info. This is in a second-story bathroom, so the radiator is at the highest point of the system.

Would it be possible to drain ONLY this radiator by opening only this bleeder valve? The water other radiators on this floor should not drain out, since there would be no way to get air into them -- is that correct?

Thanks again for the detailed explanation.

Mike T., Swampeast MO

Genuinely impossible to drain a single radiator. You have to drain the system to below the level of that rad. Do however open ALL of the bleeders on the rads on that floor when lowering the water level. It is possible for a rad to trap some water (because air can't get in). This will make you think the entire system is drained to the required level when there's actually some water above that will eventually level out and might come flooding through when you go to remove the radiator.

Rich Lytle

Makes sense, thanks

Bill Huber

Followup: reinstalling a radiator

Thank you for your good advice. Here's a follow-up: having removed a radiator (much like the one in the original photos) in order to redo a floor, I anticipate the new floor will be appreciably thicker than the old: maybe by 1/2 inch or so. How does one go about raising the inlet and outlet pipes to compensate? Is it a routine matter to thread custom-cut sections of pipe (1" o.d.) for jobs like this? I don't mind bringing in a pro, but it seems this sort of thing must happen a lot and the solution should be straightforward. Thanks.

Mike T., Swampeast MO

Often the piping will have sufficient play. If not and you only need ½" or so, you usually have to remove the last section of pipe and replace with one the required amount longer. There are "extension couplings" (can't remember the proper name), that are female on one end and male on the other (both same size) but they'll add significantly more depending on the pipe diameter.

Sometimes the radiator feet are recessed into the floor. Other times the radiator feet are cut. Personally I wouldn't do these if the other end of the pipe that needs to be extended is accessible. I've successfully re-coupled a couple long risers inside a finished wall before, but was prepared to open the wall and just got lucky...