How to Bleed Underfloor Heating

A Guide to Releasing Air From Underfloor Heating

Bleeding Underfloor Heating

Underfloor heating is an increasingly popular option for homeowners. There’s nothing like the feel of toasty toes on a winter’s night.

Whether you already have underfloor heating or you’re considering having this type of heating system installed, it pays to be aware of the level of maintenance involved.

Underfloor heating systems actually require very little care and attention and a wet system is very similar to the central heating systems most of us have at home.

That said, there are a few basic underfloor heating tips that it’s wise to take on board if you do have underfloor heating.

If you know what you’re looking for and how to address minor issues, you can leap into troubleshooting mode straight away and hopefully, rectify any problems that affect the efficacy of your heating system.

One issue you may encounter with underfloor heating is air becoming trapped in the system. This is similar to the kinds of issues you may have dealt with when using standard radiators – check our bleeding radiators sequence guide.

Although the air in the pipes is unlikely to be a major problem, it can affect the amount of heat that the system generates. Bleeding underfloor heating can help to resolve issues and maximise heat flow.

If you suspect that you might need to bleed your underfloor heating or you’re keen to learn more just in case this is a job you have to undertake in the future, hopefully, you’ll find this step-by-step guide useful.

Release Air From Underfloor Heating

How to Bleed Underfloor Heating: A Step-by-Step Guide

Bleeding your underfloor heating system is not a job that you’ll be required to undertake on a regular basis, but it’s always good to be prepared.

If you spot signs that your heating isn’t working as well as it should be, this may mean that there is air trapped in the pipes. If this is the case, you have two options.

You can either attempt to bleed the system yourself, or you can call and seek advice from professionals.

If you’re keen to give bleeding your underfloor heating a go, follow these steps:


Before you Begin

  • Keep an eye on the pressure: before you do anything, take a look at the pressure in the system. If you have central heating, you may notice that the pressure tends to rise and fall, and this is the same for underfloor heating. Keeping an eye on the pressure can alert you to potential issues. If you think the system may need bleeding, check the pressure. If it is low, try adding more water and see if this makes a difference. If you are refilling the system, check for leaks beforehand. If you’ve got a leak, don’t attempt to try and carry out repairs yourself. If the pressure is dropping, this may indicate a different problem, and it’s wise to contact underfloor heating experts.
  • Check your air bleed valves: checking the air bleed valves should tell you whether or not there is air trapped in the system. If there are air pockets, this may decrease heat flow and reduce the temperature of the water. Adjusting the valves will enable you to dislodge air.


Bleeding your Underfloor Heating: What to Do

If your system is completely filled with water, the next step is to vent each port individually. It’s best to wait around 10 minutes to start doing this if you have filled the system with water.

  1. Start by bleeding the pipes in the lower section of your home to ensure that air is released at the highest point.
  2. If only part of the system is not working, isolate the area before you start the process and remove the actuator.
  3. Drain each valve individually, opening the ports using an Allen key.
  4. Ensure that only one valve is open at a time.
  5. Work methodically, moving from one valve to the next.
  6. Keep a towel or cloth close by, as water is likely to flow out of the valve during and after the bleeding process.
  7. Attach a hose, which is connected to the cold tap, to the flow valve and a hose to the drain: this enables you to drain off waste, flush out the pipes and refill the system.
  8. Repeat the process until every valve has been vented.


What to Do After Bleeding your Underfloor Heating System

Once you’ve vented the system, wait a few minutes and then check the pressure gauge again.

It is likely that bleeding the system will cause the pressure to rise and you should find that your system is working efficiently and effectively again.

If the pressure is still low, it may be worth seeking advice, as there may be more complex issues that require expert attention.


Basic Maintenance Tips for your Underfloor Heating

If you’ve got underfloor heating, it’s natural to want to get the best out of it for as long as possible. Generally speaking, underfloor heating systems don’t require intensive maintenance and you should find that you don’t encounter troubles on a regular basis.

It’s a good idea to check the pressure frequently and make sure that it’s in the desired zone. If the pressure is low, add water. If the pressure is fluctuating or it is too low or too high every time you check, it’s advisable to get in touch with underfloor heating experts.

It’s also wise to seek advice if you have hot and cold spots, the temperature has dropped or you don’t feel that the system is working as effectively as it should be.

If there are issues, an underfloor heating expert will be able to remedy them. You can attempt relatively straightforward tasks, such as bleeding the system yourself, but if you don’t know what you’re doing or you suspect the issues may be more complex, it’s best to call the professionals.

If you think your underfloor heating system may need bleeding, hopefully, this step-by-step guide will come in handy and help you release trapped air and improve water flow.

Contact PHS Underfloor Heating Engineers

So, now you know everything you need to know about bleeding your underfloor heating system.

If you follow the steps and the pressure is still low or the system isn’t working properly, just call our team on 0208 252 8927 or use our contact form to schedule an appointment with one of our expert UFH heating engineers!