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Why Does Boiler Pressure Drop?

Does your boiler keep losing pressure? If yes, then you need to find out why as soon as possible. Low boiler pressure is one of the most common causes of boiler problems and can be a sign of leaks and faults. Find out below why your boiler pressure has dropped and how you can fix it to avoid costly repairs later down the line.

What exactly is boiler pressure?

While all central heating systems carry a volume of water, new boilers do not use storage tanks and instead use an expansion vessel. As the water volume increases and decreases with temperature, this expansion vessel does the job of absorbing any pressure changes when your water is heated up.

Naturally, you want your boiler to work at its very best, so it needs to operate within a pressure range of 0.7 bar and 2.5 bar. If the pressure falls below this range, then it can typically be topped up using a filling valve.

How you can check if your boiler pressure is low

If you think that your boiler pressure is too low, your first port of call should be your boiler manual, as this will be able to tell you how to check your boiler pressure. Modern boilers, i.e., combi boilers, often have a screen on them that will flash with an error code to show that they have low boiler pressure.

You should also be able to check the pressure gauge, which will indicate if your water pressure is low, adequate, or high.

Common signs that your boiler pressure is low are:

  • You only have access to cold water
  • Your boiler heats water very slowly
  • Your radiators aren’t warming up properly
  • The pressure gauge on your boiler has fallen

Why is my boiler pressure low?

There are several reasons why your boiler has lost pressure, including:

  • There is a leak from the appliance or on the heating system. This is typically from radiator valves or system components.
  • You have recently bled a radiator, and air or water has been released from it.
  • Your pipes and radiators have corroded or loosened over time.
  • You have a boiler leak.
  • You have a faulty boiler part.

If you suspect that the problem is with the boiler itself, you should call a professional immediately. Look for a Gas Safety Registered heating engineer Thurrock based or one in your local area. Do not try to undertake boiler repairs yourself, as this can be extremely dangerous.

How do I fix low boiler pressure?

If there is no leak or fault with your boiler, you may be able to increase low boiler pressure yourself. You need to locate the filling loop that is attached to your boiler. This is usually made of silver and features a handle valve and an isolation valve on each end of a pipe connection.

Using a flat-head screwdriver, turn the isolation valve anti-clockwise until the line on the valve is in line with the pipe. Then turn the handle valve anti-clockwise to enable water to enter the system. Keep an eye on the pressure gauge until it has returned to normal levels. Finish by closing both the valves. When your boiler pressure is back to where it should be, the error code on your boiler should disappear, and your boiler should function at its best again.

Does your boiler need repairs? Or perhaps you need a new boiler installed? Our gas boiler engineers Essex team is standing by to help you heat your home without breaking the bank.



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