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Who knows what the issue is until you inspect the boiler system? We understand it is frustrating to know there is no hot water available for your needs despite spending money on your heating system. But don’t be mad at your boiler, that’s its parts not functioning properly. You can inspect the boiler yourself and resolve the low-pressure problem.
We will explore all the potential problems and their solutions in this article. So, bear with us for a moment as we help you find out the issue causing your boiler to lose pressure. This problem commonly occurs in modern combi boilers (we will tell you why), we will provide the solutions for Combination boilers.
Before we discuss the causes and solutions in detail, you need to understand how boiler pressure works, how to check it, and what is the normal range. So, bear with us for a brief moment, promise it won’t be heavy talk.
What Is A Boiler Pressure?
As we know, modern combi boilers do not have a water storage tank. Instead, they use the main water source to get water heat it, and supply it for central heating and domestic use. These modern boiler systems use expansion valves to create pressure and push the water.
The normal water pressure depends on your household requirements. Yet, the normal water pressure ranges from 1 to 1.5 bars (when central heating is off).
For both central heating and domestic use, a pressure of 0.7 to 2.5 bars can be normal. You can check the pressure on the pressure gauge on the front of your boiler. The green colour on the gauge is for the low pressure side while Red represents higher pressure.
What Are Common Reasons for Boilers to Keep Losing Pressure?
There can be several types of minor issues that can cause low water pressure. Below are some obvious ones you should check first:
- A leak in the pressure release valve can ditch your boiler and ruin its reputation.
- Issues with the expansion vessel can also reduce water pressure.
- Leaking heating pipework can also be the reason behind lower boiler performance.
- Have you bled your radiators recently? Opening the radiator valve entirely can reduce water pressure dramatically.
Along with these common reasons, having a damaged and malfunctioning boiler can also be a cause of losing pressure in your boiler. If none of these parts is causing issues, you might need a professional to check the heating system.
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How Can You Solve Boiler's Low-Pressure Problem? Step-By-Step
To solve an issue, you need to find the root cause of that problem. You should inspect different parts of your boiler and see what’s causing the low pressure. Most of the reasons can be solved all by yourself and we will tell you how.
So, without further ado, let’s catch the culprit for making you struggle with heating and hot water supplies.
1. Leakage in the Boiler
Just like other boilers, combi systems also have various leak points. The most obvious leakages can occur in parts like:
- Ring Joints.
- Diverter Valves.
- Air Vents.
- Automatic Air Washers.
- Heat exchangers.
While the major leaks can be noticed effortlessly, small internal leakages can be missed as water drips on another surface rather than below the boiler. While these leaks are not dangerous, they can reduce the performance and pressure of your boiler.
How to Repair Boiler Leakages?
First of all, you need to determine the seriousness of the issue. If you see a water pond under the boiler, contacting a safe gas engineer for inspection is the best call. However, if little dripping and leakage from ring joints, valves, or air vents are causing the issues, tightening and a little duct tape can do the job.
You should not open the boiler or try to repair major issues yourself as you might end up paying for boiler replacement instead of its parts. However, the repair costs depend on the damage caused.
2. Leakage in the Pipework
If your boiler comes clean, the issue might lie in the heating system infrastructure like pipework and ductwork. You need to wear your investigative lens and see around the pipework around the house.
You should also carefully check the joints and bends as they are more likely to have a leakage. You should be able to locate the leakage as you will be looking for a puddle of water (same as boiler leakage)
Solution for Pipework leakage
As a first thing, you should turn the isolation walves off to turn off the water supply from the boiler. If the leakage is minor, you can use self-fusing silicone tape as a temporary solution.
You can also use sealants for leaking pipes depending on the damage. However, these are temporary solutions that will make your system run again, but you need a permanent and professional repair later on.
3. Damages to Pressure Relief Valve
Do you know what pressure relief valves are designed for? Yes, to release the pressure excessive pressure from the system. This is usually used when pressure exceeds 3 bars. A faulty pressure relief valve (no matter internal or external) will create low pressure or start dripping.
In case it’s dripping, it will start leaking water from the central heating system at low pressure to the condensing pipe (the pipe outside your home which deposits the water to the sewer).
Replace the Concerned Valve
Of course, you’ll not replace it yourself. Your job is to determine if the pressure relief valve is causing the issue or not. If the valve is detected as faulty, you should contact the safe gas installer nearby and let them do the rest of the job.
4. Damages to Expansion Vessel
The expansion valve is responsible for keeping a stable pressure in your heating system and boiler. A faulty expansion vessel rises can cause inadequate pressure in the system. First, it raises the temperature beyond 3 bars, and when pressure is released through the pressure relief valve, it drops the pressure significantly instead of stabilising it.
This vessel needs annual repressurising, if you are not maintaining your system well, you might experience low pressure of the boiler.
Repair the Expansion Vassel
To prevent this issue in the first place, you should re-pressurise this boiler part annually. To resolve this issue, you can contact the installers to check if repressurising the vessel can solve the issue or if you need repairs. However, the expansion vessel is not a costly repair or replacement, so there is nothing to be worried about.
5. Broken Boiler Parts
If none of the above are creating the problems, you should consider if your boiler is making weird noises along low-pressure. The low pressure can also be caused by broken boiler parts (internal or external). If that’s the case, your boiler monitor will also show if something is wrong with your combi boiler.
Replace the Broken Parts
No, don’t open the boiler or try to repair the damages yourself, call them whose job is to do this. You need to immediately call the licenced installer and do a check-up of your boiler. However, these signs are often seen in older boilers. If your boiler is also older, this might be the perfect time to replace it with a new one.
Don’t be offended, there are various government grants available through certified installers and local councils. You just need to contact safe gas installers like Grant Boilers and they will handle everything for you. However, you still need to perform your part and that’s providing accurate information and documents.
Final Thoughts
Finding the root cause of your boiler losing pressure is the only quick way to get it resolved. However, in extreme cold weather conditions, the cause might be different from that of moderate conditions. For example, frozen pipes can also be a major reason for the low pressure of the boiler.
So, you should every aspect or potential reason for this problem and see if you can resolve it yourself before you call an expert.
If the issue remains persistent and you are not able to understand the cause, calling the professionals is a safe and quick option. Of course, you can not wait weeks to determine the reason for the boiler losing pressure.
Frequently Asked Questions
Technically yes, if your investigations result in finding no leakage, low pressure might be caused by faulty parts. Parts that are responsible for creating and releasing pressure can cause the boiler to lose pressure. Those parts include the expansion vessel, pressure relief valves, or bleeding the radiators.
Well, a good boiler should never lose the pressure. However, when you release pressure through relief valves or bleed the radiators, you might experience a temporary time period. But that’s only one to two times a year. If your boiler is frequently dropping the pressure, you should consult some professional installers and get it repaired.
The expansion vessel is required to be re-pressurised at least once a year. Depending on your home’s capacity and heating system, you might need to top up twice a year. If you do not top it up, you might face low boiler pressure and inadequate heating.
