Power Flushing For Boilers

Boilers are closed systems – or about as close to closed as we can get in the world of central heating. That’s a huge advantage when you compare them to other systems like furnaces. Boilers don’t need filters, nor do they require vents. This makes boilers an excellent choice for people with allergies. It’s hard to get a boiler system dirty!


But that doesn’t mean that boilers never need to be cleaned. There’s a lot going on in a boiler: Water heating up and interacting with metal parts. Gas being burned. Corrosive water getting drained. All of these interactions are tightly controlled, but over time, they can lead to build-up in your boiler. That’s when you need a power flush.

What Is a Power Flush?

A power flush is a professional deep clean of your boiler. First, a technician will connect a machine known as a pumping station to your boiler. This machine can pump high-pressure water through your system. Depending on the type of boiler you have, it may be attached to the pump head (if you have a combi-boiler) or the circulation pump (if you have a regular boiler, sometimes called a system boiler).


The pumping station flushes your system using high-pressure water, though in many circumstances your system will also be pumped with a number of different chemicals. These chemicals remove sludge, rust, and limescale. They’ll also flush your system with a corrosion inhibitor to prevent future rusting.


Some areas of your system may be particularly soiled with sludge. In these cases, your technician will use power tools to dislodge the sludge. 


Once all of the sludge, rust, and other contaminants have been dislodged, your technician will flush the system again using clean water. They’ll then safely dispose of the water and all contaminants. 

What Are the Advantages of a Power Flush?

Power flushing your system can:


  • Increase the lifespan of your boiler
  • Restore functionality to your boiler
  • Increase your boiler’s efficiency
  • Improve comfort in your building
  • Reduce the noise that your system makes


It’s like a spa treatment for your system – your boiler, pipes, and radiators will all be rejuvenated. Your system will work better, heat faster, and last longer. Power flushes are incredibly useful. 


What Are the Signs That My Boiler Needs a Power Flush?

Does your boiler need a power flush? It might. If…


  • You constantly need to bleed your radiators
  • No water comes out when you bleed your radiators
  • Discoloured (black or brown) water comes out when you bleed your radiators
  • Your boiler and radiators make a lot of noise
  • Your radiators are cold, but the pipes leading to them are hot
  • There are cold areas on your radiator, especially toward the bottom
  • Your boiler needs to be restarted frequently
  • Your boiler pump has failed
  • Your tap water is cloudy (in the case of a combi-boiler)


…then you probably need to have your boiler flushed. Call a professional to check on your system. You may only need a pumpless chemical flush, which is less expensive than a power flush. On the other hand, there may be components of your boiler that have broken as a result of all that sludge. In that case, you might need repairs as well. 

How Often Does My Boiler Need a Power Flush?

There’s no definitive answer to this question, as it depends on the type of boiler you have, how well it’s maintained (whether you use anti-corrosion treatments, etc.), and other factors. Boiler owners in Winnipeg are pretty lucky in that our water isn’t particularly hard, which means boilers in our city are less prone to limescale build-up than elsewhere.


With all that being said, we’d estimate that most boiler owners will need to get their system power flushed every 5-6 years. Again, this number can vary depending on the type of boiler you have, how many rooms it’s heating, and more. If you’ve noticed any of the signs we listed above, it’s a good idea to call a professional to see whether or not flushing is the best course of action. 

How Long Does a Power Flush Take?

Much like the previous question, there’s no one answer to this question. For a three-bedroom home, the entire process might take about 6-8 hours. Factors that can influence this timeframe include:


  • The age of the system
  • The amount of time that has passed since the last power flush
  • How much sludge has accumulated in your system


This means that the process might take half a day – but it may also take several days. Part of the equation is how much time you and the technician have – a job might take 12 hours but need to be spaced over the course of two days.


How Much Does a Power Flush Cost? 

Power flushes are safe and effective, and often worthwhile – but they can be expensive. As always, it depends on the size of the system being flushed, as well as how much build-up there is in the system, but a power flush costs hundreds of dollars.


This can be very worthwhile, especially for younger boilers. The cost of flushing the system can often be recouped. First, you may recoup it financially because your system will be more energy-efficient, you’re less likely to need repairs, and you won’t need to replace your boiler right away. Second, your building will be much more comfortable – an intangible gain, to be sure, but one that we think is important.


Sometimes, however, the cost of a power flush is not worth it. In those circumstances, we recommend replacing your boiler. This is often the case if you need a power flush and a number of replacement parts, or if your boiler is quite old.


Power flushing can increase the efficiency, lifespan, and comfort provided by your boiler system. We offer boiler maintenance in Winnipeg, including power flushing. By getting your boiler maintained regularly, you reduce the chances that you’ll need a power flushing. Even with routine maintenance, however, you’re still likely to need a power flush a few times during the lifespan of your boiler.