What causes a boiler to lose pressure? The most common reasons for a boiler to lose pressure are: Releasing air or water from a radiator when bleeding it. A leak from the appliance or on the system most commonly from radiator valves or system components.

Is it normal for boiler pressure to drop slightly?

In most cases, low boiler pressure is nothing to be concerned about, but if you do have concerns you should always seek the advice of a registered Gas Safe Engineer. Typically, low boiler pressure means water can’t be circulated around your system or delivered to your taps and showers.

Can a central heating system lose pressure without a leak?





Boiler Losing Pressure, No Leak



In 99% of cases, a boiler losing pressure means a leak — it’s as simple as that. Unless the dial sits at 0 even when topped up (which could be a sign of a faulty pressure gauge), there’s a leak somewhere – even if you can’t see it in the boiler or the heating system.

Why does central heating keep losing pressure?

Pressure loss may be caused from a leak in the pressure relief valve, an issue in the expansion vessel, air in your system, or a leak in the heating pipework itself.

What do I do if my boiler pressure keeps dropping?

Top tip!

  1. Switch off and allow your boiler to cool.
  2. Double-check that both ends of the filling loop are securely attached.
  3. Open both valves, to allow cold mains water into the system (you should hear it)
  4. Wait for the pressure gauge to read 1.5 bar.
  5. Close both valves, one after the other.

How do I find a leak in my central heating system?


Quote from Youtube video: Even if the boiler is sealed as i usually are or you go outside you can smell that perfume coming out through the flue pipe. And that means that you've got a leak in your heat. Exchanger.

How often should you need to top up boiler pressure?





Ideally, you shouldn’t need to top up your boiler pressure very often. But if the pressure drops more than once or twice a year, check all visible pipes for signs of water leaks. You might also find green deposits near joins in copper pipework, or stains on the skirting boards or ceilings.

Is 2.5 bar too high for a boiler?

Your boiler should be running between the 1 bar and the 1.5 bar, which will be in the green section of the boiler pressure gauge. If the bar is hitting over 2.5 bars, then the pressure from the water in the system is too high, and anything below 1 bar is too low.

Why do I keep having to top up my boiler?

The reason we top up the system when it has cooled is that when the central heating heats up the water expands and causes the pressure to increase, this is normal and no need to worry, but if you have the initial pressure too high it means when the water heats up it will over pressurise and will then discharge through …

Is 3 bar too high in boiler?

High boiler pressure isn’t dangerous, even if it’s showing as three bar on the pressure gauge. In most cases, the boiler will turn itself off if the pressure goes about a certain level and a working PRV should successfully control the pressure, preventing it from getting too high.

Does running hot water reduce boiler pressure?



High boiler pressure can have a variety of causes. But before getting into those, it’s important to note that your boiler pressure will naturally rise whenever your heating or hot water is in use. This will cause a spike in the reading but there’s no need to panic because it’s normal.

Can you bleed radiators when heating is on?

Should I be bleeding radiators hot or cold? Always make sure your central heating system (your boiler) is turned off and your radiators are cold before attempting to bleed them. When turned on, your radiators contain hot water, and you could be at risk of scalding yourself if you bleed them at this time.

Can a dripping tap cause boiler pressure to drop?

No because that would be just like a dripping tap which wouldn’t affect the pressure.

How do I know if my expansion vessel is faulty?



If you think the vessel has failed, unscrew the plastic cap from the pressurisation valve (it’s like a car tyre valve). Momentarily depress the pin in the valve to release a little pressure. If water comes out of the valve you have a definite expansion vessel fault.