How to Drain a Radiator Boiler

What You'll Need
Owners Manual

A radiator boiler is what heats the water in your system and will move it through your radiator through a series of different pipes. Over time, you may find that the boiler will stop working as well because of things like rust and sediment. In order to prevent this from becoming a problem, you should make a habit out of draining and then refilling your radiator boiler at least once a year. This will help to keep your water heater working for much longer and cause a lot less problems over time. You will find that with the right tools and know how, draining your boiler will be a fairly simple process. However, it is very time consuming.  

Step 1: Turn off System

You will need to begin by first shutting off the entire system. After you have done this, you will need to close off the water feed valve that goes to your boiler. The system will need time to cool. This could typically take up to two hours to cool completely. You will need to shut off the circuit by turning it off at the main service panel in your home.

Step 2: Attach Hose

A garden hose will work fine for this next step. You will need to connect one part of the hose to the drain valve on your boiler. You will be able to find this valve on the bottom half. You will need to set the other end of the hose to some sort of drain or a sink. The most preferable place is an outdoor drain. This is in case the hose loses contact with the drain there will be less of a mess to worry about if it is outside.

Step 3: Open Vent

Once you have the hose in place, it will be time to open up the air vent. You will need to open up the air vent at the absolute highest radiator. This is done to help to break the vacuum. Once you have opened the air vent completely, you will need to open up the drain that is on your boiler; doing this will allow your system to begin to drain.

Step 4: Radiator

After your water has completely drained, you will need to close up the radiator valve. From there, the feed valve will need to be opened up. This will be so that the water can flush through the boiler. You will need to do this until the water runs completely clear and clean. After the water has turned clear, you will need to close up the drain valve that is on your boiler and from there you will need to let the system refill itself back up.

Step 5: Restart Boiler

You will need to restart your boiler so that you will be able to purge all of the air that is currently in the system. For any additional or more specific instructions, it is always a good idea to have the owner’s manual nearby so that you can refer to it as well.