Having a water softener hooked up to your plumbing is a good idea if you've got hard water. It can extend the life of your pipes, your fixtures, and even the radiators and boiler of a central heating system – all by preventing limescale from building up and clogging pipes.
However, having a water softener can also have a negative effect on your hot water heater. Specifically, it can cause problems with rust. Rust leads to leaks, and leaks can lead to needing to replace a hot water heater completely. That makes it crucial to properly maintain your hot water heater if you have a water softener.
What Causes Hot Water Heaters To Rust – Or Not To Rust?
The tanks of hot water heaters are usually made of steel with a protective layer of glass between the water and the metal. This is because the steel will gradually rust if it comes in contact with water. Imperfections in the glass can allow water to contact the steel; the design of the tank may also mean there are small areas where water contacts the metal.
However, this isn't usually a problem, and that's due to one special feature: the sacrificial anode rod. This rod is screwed into the tank so that it is submerged in the water, and it is made of a metal – usually magnesium or aluminum – that is more prone to rust than steel. As long as the rod is in good condition, it will corrode instead of the steel in the tank.
How Long Does An Anode Rod Last?
Generally, you can find out how long your anode rod is expected to last by looking at your water heater's warranty. A six-year warranty means that the manufacturer of your tank expects the anode to last about six years.
However, water softeners use salt to soften water. And salt speeds up the process of rusting metal. That means that your hot water heater's sacrificial anode may be corroded much more quickly than you would expect; it may only last for a year if you have very hard water and use a lot of salt to soften it.
How Can You Ensure Your Water Heater Won't Rust?
The number one thing that you can do to keep your water heater in good condition when you have a water softener is to check the anode rod annually and replace it when it becomes corroded. You can check the condition of the rod yourself by unscrewing it from the tank and pulling it out; be sure to shut off the power and water to your tank first.
If the rod looks corroded, you should call a plumbing supply company and order a new sacrificial anode. Different tanks require different sizes of rods, but the supply company should be able to tell you exactly what you need if you give them the make and model of your hot water heater. A professional plumber, like McDermott Plumbing Service and Repair, can also take care of this for you.