Cleaning heavy rust from the inside of cast iron radiators

Mikey_4

I have an old gravity system with 5 cast iron radiators that I want to clean.  The boiler is being replaced and I am currently at a stage where I am able to isolate each individual radiator from in the basement and fill with a "cleaning solution" .  Has anyone had positive results in cleaning rust from the insides of cast iron radiators. What type of cleaning solution, concentration, and dwell time was used. Is there a Manufacturer out there that makes a reasonably priced high temperature water filter that can be plumbed in for the new boiler, or would an ordinary strainer w/20 mesh be adequate.

Thanks,

Mike

kcopp

if you really...

are bent on cleaning they radiators you will need to pull them outside and flush them out. I have done this on a couple of occations when I converted them from steam to HW. A lot of junk. I used a wand od 3/8" copper tubing w/ holes on the last 6" to blast water up and in the sections. Then I added Fernox to the system one they were up and running. What is the new boiler? If it is a mod con you need to be careful about all that junk getting back to the boiler and possbly damaging the HX. kpc

Mikey_4

Cleaning radiators

I don't think taking the radiators outside to clean them and then bringing them back in is an option for me, at least not for the ones on the second floor. 15 sections two column, just too heavy and maybe not worth the effort. I did take the elbows off of one of the rads on the first floor and looked thru and did not like what I saw. 

I am considering a triangle tube mod/con (maybe I shouldn't be??) and would like to take precautions to protect it and any other equipment from debris that will flow out of the old radiators. 

I don't think the condition of my radiators are any worse than the next guys, but as you said, just trying to be carefull about it. 

More suggestions are welcome

Thanks,

Mike

Jean-David Beyer

On not cleaning radiators.

Of course it is easier not to clean the radiators. If you are worried about crud getting into the heat exchanger, you could put a dirt separator in the return line to the boiler. One like this, for example:



http://www.caleffi.us/en_US/Technical_brochures/01137/01137.pdf



The advantage of this kind of dirt separator over a Y-strainer is it is much less likely to get clogged and restrict water flow through the heat exchanger.



If a new boiler is a mod|con, it may need primary-secondary piping. In that case, you might use a hydraulic separator instead, like this one:



http://www.caleffi.us/en_IT/Technical_brochures/01076/01076.pdf



Not only does this replace the closely spaced Ts, it has an air separator and a dirt separator in it.

tim smith

Another option

Tie return and supply's together with a circ pump. Fill with hot water and boiler cleaner and let circ for few days. Then flush real well with fresh water. could do a quick connect with large rubber hose and a fill bib and would probably do ok.

icesailor

Cleaning rust:

That big chunk of rust you want to clean out of the inside of those radiators may be the only thing between the water and the outside of the radiator.  I'd be careful of unintended consequences. No good deed goes unpunished.

Mikey_4

Dirt separator solution

Thanks everyone for all the suggestions. The dirt separator type of solution looks like a good one at reasonable cost.  Calleff claims to seperate down to 5 microns.

Mike

nikevan

The best way to flush cast iron radiators

what is the best way to flush cast iron radiators. Inside the house or outside? Could one use high pressure pumps with chemicals or fill them with chemical solution and then after time flush them with clean water. After cleaning what is the best way to retaerd the development of rust till the system is filled with water.

nikevan

The best way to flush cast iron radiators

what is the best way to flush cast iron radiators. Inside the house or outside? Could one use high pressure pumps with chemicals or fill them with chemical solution and then after time flush them with clean water. After cleaning what is the best way to retaerd the development of rust till the system is filled with water.