Cleaning the inside of radiators

Al Letellier_9

I think trying too hard may get you in trouble. A good rinse with a hose should do the job. Don't overdo a good thing, those all rads could be on the verge on leaking anyway. Overcleaning or using any chemicals may hurry along the process.

Tim_41

cleaning rads

I am starting to work on my own house for once. I am doing the heat system over. Removing the boiler from the 3' crawl space etc. We are putting some cast iron rads in the new living space. 1921 Corto's that I traded some work for. They were steam but we are using hot water. After I sand blast them I would like to clean the insides as best possible. I have used a hose on some rads once but is there a proper way to really do a good job to get the accumulation of dirt etc out? Thanks
Tim S

Mike T., Swampeast MO

I flush them with water in three positions--normal, laying on the side and upside down. Rads used on steam systems tend to have more corrosion and scale than those used on water systems, but they probably have a lot of life left in them. I'd agree with Al not to use chemicals--just water. Make sure you use a wye strainer in the return before the boiler--most certainly if you're using a condensing/modulating boiler.

Molybdenum based treatments are [supposed] to be very good for old systems. At normal concentration they act as corrosion inhibitor--at higher (often 2x) concentration they act as a cleaner. Particularly if using as a cleaner, you should install a side-arm filter and circulate for weeks cleaning the filter frequently.

Tim_41

Thanks guys. Thats how I did my other rads when using a hose. I will for sure use a filter. Thats a great idea. It will be a mod/con going in. We also plan on installing a solar H2O system. It should be a good system. I just need to get it done before the snow flies.