Know how to bleed your loft radiator in 6 steps

Your radiators would have been a real lifesaver during those cold winters. They heat the air inside your house, providing you warmth & protection from the harsh winters. 

Your loft radiator can be a steam radiator, baseboard radiator, or a hot water radiator. Irrespective of the one you own; it is important that you bleed your loft radiator once in a while for efficient heating.

This article will discuss in detail how to bleed your loft radiator in 6 steps. Before we dive in, let’s have a look at the commonly found issues with loft radiators.


The commonly found issues with loft radiators

Let’s begin with steam radiators. A steam radiator uses a boiler to heat water and the steam released heats up the room. As boiling is not an instantaneous process the whole process takes time. Thus, this system is only capable of providing intermittent heating and cooling to your house.

Clean vents are the key to the proper functioning of a vented system. Dusted vent fins can induce an insulation effect and the heat absorption rate from the hot-water filled pipes diminishes.

Now that, if you are relieved that your radiator falls in the hot water category, that is not the case. The hot water radiator works in a closed loop with entry and exit points for hot water. The heat from the radiator cools down the water, which is heated again at the boiler.

Hot water radiators tend to have the problem of air getting trapped at different locations. And the process of removing this entrapped air is known as bleeding. You would have noticed a valve on top of those radiator grills. They are there to bleed the valves to release any entrapped air in the system.


How do I know when it is time to bleed my loft radiator?

There is no fixed time interval after which you should compulsorily do bleeding. Your radiator itself will show you some symptoms when it is time to.


Let’s see what those are:

Differential heat: Touch the top and bottom ends of your radiator and see if you feel a temperature difference. Ideally, both ends should be equally hot. The difference in temperature at both ends implies that the hot water is blocked from circulating inside the radiator preventing heat gain. This mostly happens due to the air that gets trapped in the radiator.

Cold radiator: This can be a serious symptom, and mostly caused due to trapped air which blocks the flow of water into the radiator. If this shows up, we advise you to seek the help of a heating engineer.

Molds or damp patches on the walls: This is a common symptom of radiator malfunctioning and needs immediate attention.

Rattling noise from radiators: Radiators when producing rattling noise are trying to seek your attention for a check-up and further bleeding.


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How to bleed your loft radiator in 6 steps?

Before we discuss the steps involved in bleeding a loft radiator, let’s look at the tools you need for the task.


What are the things you will need to bleed a loft radiator?

  • Radiator key
  • Bucket
  • Cloth
  • Safety gloves (if-else you will learn hot water can cause burns)

Dress your floor and yourself inappropriate clothes as you are dealing with something hot.


Breaking down the procedure to its simplest, we have you a step by step guide.

  1. Diagnosis
  • Turn the heat on and give enough time for all your radiators to warm up.
  • Once all the radiators have warmed up, it’s time to carefully check your radiators one by one. Check for any rattling noise and if there is any coldness at the top of the radiator. If you found any, then you will need to bleed it without a doubt. Don’t forget to use your gloves.

  1. Open the bleed valve using a radiator key
  • Keys of different sizes are readily available. You have to find the right fit from the nearest hardware store.
  • If you happen to fail to get the right fit, you can use a wrench or a screwdriver to open the bleed valve.

  1. Turn off the heat source
  • Turn off the heat source and give it some to cool itself completely.

  1. Open the radiator valves
  • Open both the entry and exit valves.
  • You will hear a hissing sound as the air gets released wait until the hissing stops.
  • Hot water will replace the air that is being released. Ensure that you open the valve just enough for the air to escape and not too much.

  1. Remember the cloth
  • Water will be spluttering and you should be placing a cloth on the floor.
  • Your clothing should also be protective enough from the spilling hot water.

  1. Give it enough time to release all the entrapped air
  • Once the fresh stream replaces the air-entrained, that hissing sound goes off.
  • You can now tight the screw and check for any leaks.
  • Splashed water should be cleanly wiped.

You can repeat all these steps to every radiator that requires bleeding. Annual bleeding of your radiators is advisable for a well-maintained heating system. Removing the air from the system will reduce the total pressure in the system. So, to compensate you need to top up your boiler with water.

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2 Comments

Loft Flooring

Date 6/25/2021

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Date 11/17/2021

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