No Pressure In Boiler But Still Working: Check These Things First

A functional pressure gauge is essential for ensuring the safe and efficient operation of a boiler. The pressure gauge is used to measure the pressure of the water in the boiler, and provides a visual indication of the pressure inside the system. This is important because if the pressure inside the boiler exceeds safe levels, it can lead to serious safety hazards such as explosions or leaks.

If you come across a situation where the pressure gauge is showing less than 1 bar or even zero but the boiler is still working, this usually indicates the system is about to fail.  But this isn’t always the case.  Here, we review when the boiler might still work with zero pressure.

No Pressure In Boiler But Still Working

If the heating and hot water are working fine for long periods, even when there is no pressure, this means the pressure gauge is faulty.  The needle can get stuck at zero and not move even when the heating is on.  Sometimes the gauge is simply clogged up with debris and won’t need replacing. 

No Pressure In Boiler But Still Working

Warning signs like low pressure that could indicate an impending boiler breakdown

Why the Pressure Gauge is Important

The pressure gauge plays a critical role in boiler safety by allowing operators to monitor the pressure inside the boiler and take corrective action if necessary. If the pressure gauge indicates that the pressure inside the boiler is too high, operators can take steps to reduce the pressure and prevent potential hazards.

Similarly, if the pressure gauge indicates that the pressure inside the boiler is too low, operators can take steps to increase the pressure and ensure that the system is functioning properly.

What causes low pressure in a boiler system and how to fix it

In addition to its role in boiler safety, a functional pressure gauge is also important for ensuring the efficiency of the boiler. If the pressure inside the boiler is not at the correct level, it can affect the performance of the system and lead to increased energy consumption or other issues.

Pressure gauge defects

A faulty pressure gauge can lead to a number of issues, including inaccurate pressure readings, leaks, and damage to appliances and fixtures. There are several symptoms that can indicate a faulty pressure gauge, including erratic or fluctuating pressure readings, a gauge that is stuck or not moving, or a gauge that is not reading any pressure at all.

These symptoms can be caused by a variety of issues, such as a damaged or broken gauge, a clogged or blocked pressure line, or a faulty pressure regulator.

To identify if a pressure gauge is not working correctly, it is important to first check the gauge itself for any visible damage, such as cracks or leaks. Next, check the pressure line for any clogs or obstructions that could be affecting the pressure readings

You may be able to remove and inspect the pressure gauge on certain boiler types that are underneath the boiler and you don’t need to open up the casing.  But some are built into the casing while others are digital.

It is a good idea to change the gauge as it helps to diagnose some faults but is not necessary for the system to function.    

If there is a genuine loss of pressure, the boiler will not fire up to start with and show a fault code.  On the other hand, if the pressure goes over the safe limit, the pressure relief valve will work to displace some of the system water to bring it back down.

Why boiler pressure drops when the heating is off

Call a professional if necessary: If you are unsure about how to diagnose or fix a gauge issue or any other problem with a gas or plumbing system, it is always best to call a professional to avoid potential hazards or damage.

Another possible reason is a slow leaking pressure relief valve.  You can check for any water leaking out of the pressure relief valve on the copper pipe going outside of the house.  In these cases too, the boiler can fire with no pressure showing.

When should I call a gas engineer?

If the gauge is showing no pressure and the heating turns off and won’t switch back on, it is time to call an engineer to fix it.  Too high or too low pressure will cause the boiler to eventually stop working, sometimes temporarily, sometimes until complete breakdown.

Troubleshooting a boiler that is not firing up or working properly

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Preventative Measures

Regular boiler maintenance is essential for ensuring the longevity and efficiency of your boiler, and can help prevent future gauge issues. Here are some tips on regular boiler maintenance:

  1. Schedule annual inspections: Have a professional inspect your boiler at least once a year to ensure that it is functioning properly and to identify any potential issues before they become major problems.
  2. Check the water level: Regularly check the water level in your boiler to ensure that it is at the correct level. Low water levels can cause damage to the boiler and affect its efficiency.
  3. Clean the boiler: Regularly clean the inside of your boiler to remove any buildup of dirt, debris, or other materials that can affect its performance.
  4. Check the pressure gauge: Check the pressure gauge on your boiler regularly to ensure that it is functioning properly and providing accurate readings.
  5. Test the safety controls: Test the safety controls on your boiler regularly to ensure that they are functioning properly and can prevent potential hazards.
  6. Replace worn or damaged parts: If any parts of your boiler are worn or damaged, have them replaced as soon as possible to prevent further damage and ensure the longevity of your boiler.
  7. Use a water treatment system: Consider using a water treatment system to prevent buildup of minerals and other materials that can affect the efficiency and performance of your boiler.

By following these tips on regular boiler maintenance, you can help prevent future gauge issues and ensure the longevity and efficiency of your boiler. Remember, regular maintenance is essential for keeping your boiler functioning properly and avoiding major problems down the line.

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