How to Remove an Air Lock from a Hot Water Heating System

Removing an air lock from a hot water heating system can be a straightforward process if you follow the correct steps. However, it's important to understand the context in which air locks occur and when professional assistance is needed.

Understanding the Problem

When you encounter an air lock in your hot water heating system, it can prevent the proper flow of water and heat. This issue might occur due to a variety of reasons, such as improper system design, faulty components, or lack of maintenance. It's crucial to identify the source of the problem to find a long-term solution.

Why Air Locks Occur

Hot water heating systems can experience air locks when air is trapped in the pipes, typically at the highest points of the system. Air locks are more common in systems that are not properly designed or installed. Potable water systems connected to municipal water supply are less likely to experience air locks. However, if your system uses well water, this information does not apply to your situation.

Even if you have the right design, air locks can happen if the system is not correctly maintained. Properly designed systems include devices that prevent air binding and valves that allow the system to be purged of any trapped air. If your system lacks these features, the following steps might not work.

Steps to Remove the Air Lock

The first step is to ensure that the make-up water pressure reducing valve and the air scoop are functioning properly. If either component is malfunctioning, repair or replace them as needed. Correctly operating these valves may eliminate the air lock.

If the air lock persists, close all valves in the system to disable backflow. Specifically, close valves isolating the water heater or boiler to prevent over-pressurization. Once the system is properly isolated, you can proceed with the following steps:

1. Increase Water Pressure

Opening all the faucets in the house at once can increase the water pressure in the pipes. This additional pressure may push out the air bubble. If the issue is with the hot water, you can try a simple trick: disconnect the washing machine hose and connect it to the hot and cold valves. Open both valves for 30 seconds. The pressure from the cold water line should be sufficient to push the air bubble backward and out of the pipe.

2. Use Bypass Valve

Using the bypass feature of the pressure reducing valve, observe the water flow at the desired pressure. This can help you understand if the system is receiving sufficient water pressure to push out the air lock.

3. Drainage and Hose Usage

Connect a hose to the hose bibb on the supply side of the system and route it to a suitable drainage location. Open the valve and check if the air lock is resolved. This method can help clear the air out of the system.

Professional Assistance

If your system is not properly designed or installed, or if you encounter repeated issues, it's highly recommended to seek assistance from a professional who is trained and experienced in hot water heating systems. Proper diagnosis and repair can prevent future issues and ensure the longevity of your system.

Remember, while these steps can be helpful, they may not solve every air lock issue. Professional intervention is often the safest and most effective way to ensure your hot water heating system operates efficiently and safely.