You Don't Have To Make The Same Mistakes

I always took my home's heating and cooling system for granted. That is until I found myself battling one of the hottest days in years and my air conditioner simply refused to turn on. After contacting my local HVAC contractor, I learned that my cooling coils had frozen over from a lack of maintenance. He did get my AC back up and running that day, but he also helped me to look at my heating and cooling system in a whole new light. I have spent a lot of time over the last few years learning more about how to properly maintain my HVAC system and ultimately lower my energy costs. Today, I would like to share this knowledge with you so that I can help you to avoid some of the costly mistakes I have made in the past.

Radiator Sludge: How It Forms, Problems It Causes, and How to Remedy It


If your home is heated by a hot water radiator system, you should be aware that there are a few different causes for your radiators to stop heating. Aging radiator heating systems can suffer from a buildup of sludge, causing cold spots on your radiators. Here is information on how sludge occurs, additional problems it can cause your radiator heating system, and how to remedy the problem.

Sludge Causes Problems

As your home's radiator heating system ages, the insides of its radiators and pipes can rust, creating iron oxide. When your system is ten years or older, it is likely to have a buildup of iron oxide corrosion. As this rust builds up, it will fall off into the system's water, combining with dirt in the water to form sludge. 

Sludge in your home's heating radiators will settle to the bottom of the radiators and block the flow of hot water, causing parts of the radiators to remain cold. If the top of your radiator is cold, it most likely has air bubbles trapped inside. Sludge buildup usually cause the middle sections of your radiator to be cold.

Sludge buildup can result in your heating bill to increasing your radiator system works harder. You may also increase your energy bill when you turn up your room's thermostats to try to keep your home warm. Besides causing problems with heating your home, a buildup of sludge in your radiators can also damage your boiler, your heat pump, and the valves in your radiators. To prevent this damage, you will need to remove the sludge from your heating system.

How to Remedy Radiator Sludge

To clean your heating system of sludge, you will need to flush your radiator system with clean water. Then, after the system has been flushed, you should add an inhibitor to your radiator water. An inhibitor is a chemical which will coat the inside of your system, preventing further rust corrosion. It is also a good idea to drain your radiator system at least yearly to clean out any sludge buildup and prevent problems.

It is best to have your entire home radiator heating system flushed to clean out the radiators, pipes, and valves of any sludge that may be in your system. This flush process can be completed by a professional HVAC technician and takes several hours to complete. Your home's heating system will need to be turned off and cooled for the technician to complete the flush, so you may want to do this before or after winter when you don't need your home heated. 

If you want to remove the sludge from your radiator heating system and you don't want to worry about hiring a whole-home flush, you can clean out individual radiators as a temporary fix. You can choose to clean out only the radiators that are not working fully because they contain sludge. Sludge from other areas of the system can later refill the cleaned-out radiators, but it will help temporarily improve the heating of any radiator you clean out.

How to Clean Individual Radiators

  1. When you choose to clean out a radiator, you need to turn your heating system off and let the system water cool for an hour or two so you don't burn yourself in the process. 
  2. Next, turn the radiator's manual control valve clockwise to turn the valve off. 

  3. On the opposite end of the radiator is the lockshield valve, which is the valve connecting the radiator to the water return pipe. Using an adjustable wrench, turn this clockwise until it is tight to close the valve.

  4. Place towels and a water basin under the manual control valve and locate the radiator's bleed valve. 

  5. Use the radiator's bleed key or a screw driver to open the bleed valve. You can also buy a bleed key at most home improvement stores.

  6. Next, with an adjustable wrench, loosen the nut connecting the manual control valve to the radiator. Water will begin to flow out of the manual control valve. Catch the water in a water basin. 

  7. When the basin is full, close the control valve with the wrench and dump the basin down a drain. Repeat until the radiator is empty of water. 

  8. Disconnect the nut connecting the lockshield valve to the radiator and remove the radiator to take outside. 

  9. Using a garden hose, rinse out the sludge from the radiator. When clean water flows from the radiator, you can replace it back into your home and reconnect it to your radiator system.

Use this information to help you repair your cold radiators. If you need help with this process, find professional heating repair in Bellevue, NE or in your local area.


9 February 2016