Are you noticing a drop in the efficiency of your central heating system? Does your gas boiler seem to be consuming more energy for the same output? A little investigation will help you find the culprit.
If your boiler constantly loses pressure, it will become inefficient over time and you will end up paying more for energy consumption. It might not seem like an emergency, but by ignoring the issue, you might be inviting a bigger problem.
Keeping the pressure within the acceptable range is important for the efficient functioning of your boiler. A small leak, a faulty valve, or loose joints might cause a loss of pressure. Repressurising might help momentarily, but if there is another issue, a thorough inspection by an engineer could be required.
As soon as you sense an inefficiency in the boiler output, check the pressure gauge to see if the levels are outside the acceptable range (below 1 and beyond 2 bar). You can try repressurising as a quick fix only if you are well-versed with the process. If it doesn’t help, call a professional to detect the real cause without any delay.
How To Find Out If Your Boiler Is Losing Pressure?
If your boiler loses pressure, the first impact will be on its efficiency. Since the boiler is not able to retain the optimal pressure, it’ll consume more energy to produce the desired heating.
Though it might not be apparent that your boiler is losing pressure, you can do a timely check if you notice a drop in efficiency.
Follow these simple steps to check boiler pressure:
- Check the pressure gauge (usually located at the front of the boiler or underneath) and consult the boiler manual for details given by the brand.
- Check for leaks around the radiator pipe connections. Some common observations include water dripping or water stains, and paint discolouration on pipes and adjacent skirting boards.
- Schedule a check by a qualified engineer if you suspect that there could be an internal fault.
- Get educated on how to top up. Sometimes it might resolve the problem. Else wait for the professional to arrive for inspection.
Check this section to learn about the standard pressure limits.
What Can Likely Go Wrong If Your Boiler Loses Pressure?
Too little pressure indicates that there is not enough water within the sealed system. This can lead to inadequate flow of water to heat the radiators. Hence, your appliance will start consuming more energy, which will keep increasing over time. Most pressure issues like a tiny leak or a loose joint will not stop your boiler from working completely, but they can gradually lead to major damages.
Suddenly, one day you might run out of hot water while taking a shower. You wouldn’t want that, right?
Although the pressure gauge will tell you if your boiler is losing pressure, sometimes it can be challenging to determine the exact reason for it. While pressure issues are relatively easy to diagnose and fix, it is better to handle them as soon as they crop up.
A low pressure in your boiler can result in:
- Radiators not warming up properly
- No heating or hot water
- The dial on the pressure gauge has fallen below the lower limit
If you are wondering what could be the possible reason(s), like leaking radiators, etc., check out this section.
Can You Use A Boiler When It Is Losing Pressure?
A boiler that’s losing pressure isn’t exactly dangerous. Sometimes, there can be small leaks in the heating systems like a small puncture in a tyre. This can lead to a gradual drop in pressure below the acceptable range, which is when you need to intervene.
Other than this, bleeding the radiators might lead to low pressure as it removes any trapped air in the system. You need not act immediately, but keep watch for a few days.
Can A Boiler Lose Pressure Without A Leak?
A boiler can definitely lose pressure even without a leak. A leak might be the most common cause, but it can also be due to an expansion vessel problem, a problem in the relief valve, a filling loop problem, or bleeding of the radiators.
What Are The Acceptable Pressure Limits For Your Boiler?
All modern boilers have pressure gauges where you can see the current reading. They are mostly colour-coded, where ‘green’ means within safe and recommended levels, and ‘red’ means beyond those levels. It is measured in bars and the below table indicates the standard readings.
|Central heating is switched OFF||1 to 1.5 bars on your pressure gauge||It might vary depending on the manufacturer, but generally, anywhere between 1.0 and 2.0 bars is ideal.|
|Central heating is switched ON||Around 2 bars||The needle of the pressure gauge should remain above the lower limit set by your boiler manufacturer at all times.|
In any other cases, you will notice your central heating stopping unexpectedly. The pressure levels will probably be below 1 bar (too low) or around the 3 bar mark (too high).
You will see the number rising when the heating is on and the opposite when the heating is off. The readings should normally be within the above ranges irrespective of the kind of heating.
Why Is Your Boiler Losing Pressure and How Can You Address The Issue?
There could be several reasons why your boiler is losing pressure. Let us analyse some of the important ones.
1. Faulty Pressure Relief Valve: The pressure on your boiler can approach the 3-bar sign if there is a problem like a leakage. A pressure release valve (PVR) can detect an abnormal change and release it. If the PVR is faulty, it will cause the boiler to lose pressure.
What to do: If your appliance is under warranty, call the brand engineer for a resolution. If not, then call a local expert for repair.
2. Auto Air Vent Leak: Central heating systems can collect air over time, which needs to be released sometimes. The auto air vent (normally inside the boiler casing for new combi ones) helps in the same. But, a faulty auto air vent means unwanted leakage, causing the boiler to lose pressure.
What to do: Bleeding the radiators is the best solution, but if the problem persists, check with an engineer.
3. Leaking Radiators, Towel Rails, and Radiator Valves- This is one of the most common causes behind a combi boiler losing pressure. A small leakage of water is enough to cause pressure loss.
What to do: Check all radiators, valves, and towel rails. Tighten up any loose connections. If it doesn’t work, it might need repair or replacement.
4. Bleeding Radiators: Every time some work is done on the central heating system, air gets collected in the radiators and towel rails, which needs bleeding to release the pressure. So, the boiler pressure drops every time you bleed the radiators.
What to do: Re-pressurise the boiler after bleeding the raditors. Keep a check on whether the pressure is back to the normal resting level between 1 and 2. If it still shows abnormal readings, call an engineer.
5. Vessel Expansion: The expansion vessels need repressurising from time to time, else they can affect the boiler pressure. It can also be a case of a leaking Schraeder valve. A faulty valve can cause your boiler to lose pressure.
A damaged or degraded diaphragm on the vessel can also lead to pressure loss.
What to do: If repressurising doesn’t work, you might need to replace the vessel to stop the boiler from losing pressure.
6. Leaking Soldered Joints: For an old system, the soldered joints can become weak and start leaking, causing your boiler to lose pressure.
What to do: If you can find the leak, call an engineer to re-solder the joint. Use the filling loop to top up the boiler and monitor if this resolution helped.
7. Faulty Pressure Gauge: Though unlikely, your pressure gauge might be faulty and not give a correct reading. This can be quite dangerous because you might top up your boiler every time you see a low reading.
What to do: If you see no response on the gauge even after top-up, immediately get help either from the brand or a local technician.
How To Repressurise A Boiler Till You Get Help?
If you notice your boiler losing pressure, you can try ‘repressurising’ it on your own by following a few simple steps:
- Turn the boiler off.
- Look for an external filling loop under the boiler. It will look like a short braided hose connecting two water pipes, with levers at both ends to work valves.
- If you can’t find it, refer to the manual as your boiler may have a keyed filling loop or keyless internal filling loop.
- Turn both valves so that the levers align with the braided hose’s direction. You should hear water running and gradually see an increase in the boiler pressure gauge.
- When the bar is around 1.2, shut off both valves.
- Then, notice if the pressure stays up and no water is leaking. Then, it is safe to power up the boiler.
- Again check later after the boiler cools down that the pressure doesn’t drop significantly.
Ideally, repressurising shouldn’t be done too often. But if the pressure drops more than once or twice a year, there might be possible leaks. Also check for green deposits near joints in copper pipework or water stains on the skirting boards.
If the pressure keeps dropping even after repressurising, schedule a boiler check-up.
How Can You Prevent Low Pressure In A Boiler?
Your boiler needs proper care and maintenance for better performance and longevity.
- Annual Boiler Servicing: A boiler service contract does periodic checks by professionals to ensure that everything is running smoothly. It can help you detect if something can be a potential problem in the future.
- Regular Cleaning of the Boiler: It is important to keep the boiler clean as dust accumulates. Apart from regular cleaning on the external surface from your end, you also need to get the interiors cleaned by an engineer to prevent rust and dirt.
- Check Your Boiler Pressure: Regularly check your boiler pressure and top it up whenever required. How often you need to top up pressure depends on the boiler you have, but checking the pressure gauge every couple of months will surely help. Call an engineer if you notice any anomalies.
How To Repair A Boiler If It Is Losing Pressure?
If you are sure your boiler has a leak, simply call for repair before pressurising the boiler. Do not try to repressurise it if you are not confident of the process. It might also lapse your warranty if it’s new. Rather, call the brand technicians for help.
If you are unsure of why your boiler keeps losing pressure, get it checked by a local engineer to assess the issue and get suggestions on the repair.
While your boiler losing pressure might not pose a serious threat now, it can quickly turn out to be alarming. The best course of action is to get it checked and repaired (if required) by an expert, even if it loses pressure after you have pressurised it.
How Much Will It Cost You To Fix A Boiler That Is Losing Pressure?
If your boiler loses pressure, it is commonly because of a leak or bleeding radiators. You must contact an expert to check the best possible solution if it is because of a leak. It might be as simple as checking the joints, using a sealant, examining the pressure gauge or a complete replacement of some faulty part(s).
The repair cost includes the service charges of the engineer and the price of the parts if there is a need for replacement. Don’t worry because it won’t be too high in both cases. Make sure to compare and contrast the local service provider rates and quality before you book one.
An annual boiler service is the best way to keep your boiler in good working order and diagnose problems early. This can help you limit the repair costs. Failure to get your boiler serviced annually might also invalidate its warranty.
Your boiler needs to be properly maintained if you wish to enjoy hot water whenever you want. So, at the first instance of any low or leaking pressure, take action to fix it without delay. And if you’re interested in replacing a boiler read this article on what to expect.