Is Your Boiler Getting Older? A Good Cleaning Can Keep It Going Strong

Posted on: 3 April 2015

In older boilers, it's often assumed that reduced function, signs of rust, or odd-tasting water are a death knell. However, with a little elbow grease and expertise, you may be able to get your boiler back in tip-top shape by cleaning it thoroughly and ensuring the tank is well-protected from corrosion.

Cleaning Out An Old Boiler

The first step to get your boiler in the best possible shape is to clean it out. Be sure before you start that all water has been drained from the boiler and that the power to it is completely switched off. If your machine doesn't have an on and off switch, you'll need to flip its circuit breaker before cleaning can begin. Make sure the heating elements are completely cold, as well. Finally, it's also a good idea to have a camera with you if you don't have an instruction manual for your boiler, so you can take photos to help reassemble it later.

Once it's totally empty and powered off, you can start taking it apart at the top. If you haven't cleaned it before or had it cleaned, the flue will likely be clogged. Soot and sediment buildup inside of a boiler's flue can cause it to overheat and impair its function, making it work unnecessarily hard. Remove the flue and vacuum out the soot, then use a small brush to scrub it clean. Do this for other outer sections of the boiler as well.

Next, open up the boiler tank itself and examine it. You may see a large amount of sediment and rust in the bottom, particularly if your home has hard water. As this sediment builds up over time, it can not only overwork your boiler, but also make your water smell and taste funny. Thoroughly vacuum it out, being careful not to harm the lining between the heating element and the boiler itself. Just as you did with the outer sections and flue, use your scrub brush to remove as much rust as possible.

Reassemble the boiler using a diagram or your camera, and switch it back on. You should monitor it the first time it switches on to make sure that it works correctly.

Install Or Replace Sacrificial Anodes

The metal body of your boiler tank is the most important part of it to protect, since it constantly comes into contact with water and minerals that can cause it to rust or corrode. To this end, most boilers come equipped with at least one sacrificial anode, which oxidizes more readily than the tank metal. This means oxygen particles and corrosive minerals tend to be drawn to the anode instead of the tank walls.

As boilers age, their anodes can become completely corroded. In this state, oxygen and minerals will no longer be drawn to the anode, and will instead start to work on your boiler tank. By replacing the anodes and potentially installing additional ones, you can ensure that your machine is safer from rust. 

First, examine the old anodes in your machine. If they look to be totally corroded, replace them with new ones as soon as possible. Next, if you see significant signs of rust, you might want to consider adding a secondary sacrificial anode to better help protect the tank. This can be a complicated process, depending on your boiler, so don't feel embarrassed if you'd rather let a professional handle it.

You don't have to give up on a boiler just because it's a few decades old already. Good machines can go on for quite a long time with proper maintenance. Still, if you have worried about your water heater, it's a good idea to have a professional take a look at it. That way, if you miss any hidden problems while cleaning it, they can make any needed boiler repairs, and you won't have to deal with any nasty surprises later.