How To Remove Sludge From Your Home's Water-Fed, Wall-Mounted Radiator

If your home's wall-mounted radiator doesn't seem to be putting out an adequate amount of heat, it is possible that sludge buildup is causing the problem. Fortunately, flushing sludge from a radiator is a simple task that can be performed by homeowners. Below is more information on sludge buildup as well as how to flush a radiator containing sludge:

Tools and materials needed

  • Adjustable pipe wrench
  • Adjustable pliers
  • Screwdriver
  • Heavy towel
  • Garden hose and spigot

Step-by-step procedure

1. Diagnose the problem: While it doesn't hurt to flush a radiator that doesn't contain sludge, it is good to know if sludge is the culprit for poor heating performance. The telltale sign for a radiator struggling with sludge buildup is good heat output at the top of the unit with a noticeable dropoff in temperature at the bottom. If you find this to be true of your radiator, it is worthwhile to remove it from the wall and perform a flush.

2. Turn off the heat and shut the radiator valves: Before performing any work on a radiator, you must turn off the system's heat and allow the water to cool. Hot water escaping from radiators can cause severe scalding injuries, and the only safe way to conduct maintenance is by cooling the entire system.

Once you have allowed the water to cool, you can begin shutting the radiator valves to isolate the water from the radiator. Each side of the radiator contains a valve; one valve serves to turn the heat on and off, and the other valve controls water flow. Turn off the heat control valve by rotating it all the way in a clockwise direction until it can't be turned further. On the other side of the radiator, the water flow valve will be covered by a protective cover; pull this cap off to reveal the valve stem. With a pair of adjustable pliers, turn this valve clockwise to turn off the water flow. Be careful not to turn the stem too far or you risk damaging the valve and creating a leak.

3. Bleed excess water from the radiator: After you shut down the water flow to and from the radiator, you need to lower the internal water pressure by permitting water to escape through the air bleeder valve. Place a thick towel on the floor beneath the radiator to absorb the escaping water.

With a screwdriver, turn the bleeder valve slowly in a counterclockwise direction until water begins flowing from the valve. Leave the valve open until the water flow ceases, then close the bleeder valve.

4. Remove the radiator from the wall: When the radiator is isolated from the outside water flow and also has its internal water pressure lessened, it is time to remove it from the wall. With a pipe wrench, turn the pipe fittings so the pipes are detached from the radiator; be prepared for water to leak out of the radiator. After disconnecting the pipes, lift the radiator straight up, and it will slide out of its wall bracket.

5. Flush the sludge from the radiator: Take the radiator to a convenient outdoor location and drain as much water as possible by turning it on its side. Next, hold the end of a garden hose over one opening on the radiator and ask a helper to turn on the water flow. Continue holding the hose in place while the water enters the radiator and flows out the other side; allow the water to flow for at least five minutes to ensure the radiator is completely purged of sludge. After the radiator is cleaned, turn off the hose and drain the water from the radiator.

6. Reattach the radiator: Slide the now-clean radiator over the wall bracket into its proper position and reattach the pipes on both sides of the unit. Turn on the water flow valve with your pliers and replace the protective cap. On the opposite side, turn the heat control to the 'on' position to permit the water to flow freely through the radiator. Crack open the bleeder valve and leave it open until all the air is out of the radiator and it is filled with water. Close the valve once water starts emerging from the bleeder valve and restore heat to your system.

If you're not comfortable performing this maintenance or if you find that it hasn't solved your problem, it's a good idea to contact a professional from a company like A Bailey Plumbing.