Underfloor heating comes with a full suite of benefits. It’s highly versatile and efficient, and helps create a uniform temperature across each room.
Moreover, underfloor heating systems are surprisingly easy to maintain. However, can underfloor heating get airlocked?
Indeed, it can. This is why bleeding underfloor heating is something you’ll probably have to do occasionally. To lend a hand, we at Clickbasin put together a detailed guide on how to bleed underfloor heating. Read on to learn more.
Table of contents
- What to do before you bleed underfloor heating
- How to bleed underfloor heating
- Looking after your underfloor heating system
What to do before you bleed underfloor heating
Just as with a standard central heating system, air can occasionally get trapped in your underfloor heating system. Here are some tell-tale signs:
- Gurgling noises coming from inside the system
- The system won’t be able to generate as much heat as it normally does
- The pressure might be too low
Once you’re convinced the system needs bleeding, there are a couple of things you need to check before springing into action.
First, check that all components are functioning properly, such as:
- Boilers
- circulating pumps; and
- Motorised valves
Check there are no leaks. The air bleed valves will confirm there’s air trapped in the boiler or elsewhere.
Second, check the pressure. If it’s too low, try adding water. If the system is unresponsive or the pressure remains consistently low for an extended time period, this might be a sign of a deeper underlying issue. At this point, it’s best to call the professionals.
Now you’re ready to move on to the main part of the project.
How to bleed underfloor heating
Once the system is filled with water, wait roughly 10 minutes before bleeding it. In essence, the process involves attaching a pump, which allows water to be flushed out of the drain valve found on the lower manifold bar, one port at a time.
If you’re familiar with central heating systems, you should be able to recognise many of the components of your underfloor heating system, which are quite similar to the equivalent central heating pump bleed screw, central heating bleed valve and boiler bleed valve.
Having said that, here’s how to flush the underfloor heating system step by step.
Step one: Close the following components
Close the ball valves on the flow and return valves. Then, close all heating circuits located on the heating circuit manifold.
Step two: Remove the locking caps and close the flow rate indicators on the first valve
Tip: Start with the ports heating the lower underfloor heating section of your home before moving on to those heating the upper part.
Step three: Connect the flushing and filling pump to the respective valves
Remember, the filling one is always on the upper manifold, and the flushing one is always on the lower manifold.
Step four: Open the first port, return and flow and switch on the flushing pump
Continue flushing until no more air bubbles exit the system, then close the valve.
Step five: Working methodically, repeat the same process for each remaining valve
Once done, you can disconnect the flushing and filling pump, close the two valves and replace the locking caps.
Once you’ve refilled the system with water, it’s a good idea to monitor the pressure. It should be between 1.5 and 2 bar, without major fluctuations.
If that’s not the case, chances are you have more serious problems than an underfloor heating airlock. So, call professional plumbers sooner rather than later to have the entire system thoroughly examined.
Looking after your underfloor heating system
Underfloor heating systems are fairly low maintenance when installed competently and in full compliance with the manufacturer’s instructions.
So, as long as that’s the case, all you need to do is carry out routine maintenance, such as monitoring the pressure, checking for leaks and noting any untypical dips in the overall performance.
If everything is in order, bleeding your underfloor heating system is something you’ll have to do very rarely.
Luckily, now that you’re fully aware of how to bleed underfloor heating, you should be more than equal to the task. For more info on how underfloor heating works, check out our handy guide.
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