If you have a boiler-style heating system, when you turn on the heat, the entirety of the radiator should get hot. If only part of your radiator is getting warm, then your rooms are not heating as well as they could as a result. It's important to figure out what's causing this, so you can improve your heating efficiency and enjoy a more comfortable home. Here's a look at the most likely causes of this issue, and how to address them.
If you have steam boiler heating…
The issue is likely a clogged vent. If the vent gets clogged, then pressure cannot be relieved from the radiator, and the steam may not be able to work its way all of the way up and into it. It is common for vents on steam radiators to become clogged with dust and dirt when the system sits off for the summer. Some also become clogged if they are accidentally painted when the radiator is painted. Luckily, the issue is easy to fix.
Locate the vent – it's a cylinder-shaped metal piece on the side of the radiator. It should have a small hole in the top. Use paper clip or a safety pin to poke into the hole and remove any debris. Turn your system back on, and you'll notice that air comes out of the vent and the radiator now heats evenly.
If you have water boiler heating…
In water boiler systems, the likely cause of the problem is an accumulation of air in the system. If there is too much air in the system, it displaces some of the water in the radiator, leading to partial heating. To fix this issue, you'll need to bleed the radiators.
With the system turned off, insert a radiator key into the little keyhole found at the top of the radiator. Hold a small container beneath the keyhole as you do this. Turn the key about ½ turn to the left. Air should rush out of the radiator. When water starts coming out, turn the key back to the right. Repeat this process for each radiator so you can be sure you get all of the air out of the system.
If your radiators are not heating completely, don't just ignore and "live with" this problem. As you can see from the instructions above, it's an easy issue to fix, whether you have a steam or water-based system. If you have tried to fix your radiator and failed, contact a company, like Drew Green Heating & Cooling, to fix it for you.