All Heating One

12 Most Common Boiler Problems & Solutions

It’s never ideal to have a sudden boiler problem. There are few things more inconvenient than not having access to the heating and hot water that your house requires.

1. Leakage

A problem with an internal component, such as a pressure valve or pump seal, is frequently the source of a boiler leak. If the leak is coming from your pressure relief valve, your system’s pressure is probably too high. If the leak is caused by a problem with the pump seal, it is possible that the seal has worn out.

Corrosion might be to blame for a leak that has occurred around your system’s pipes. There might potentially be a problem with the way your system was installed.


 We recommend that you seek the assistance of a skilled engineer to help you identify and resolve this problem. Your specialist may advise that you purchase a new boiler if the leak is caused by a very serious problem.

2. Inadequate boiler pressure

By looking at the built-in pressure gauge on your boiler, you can normally tell whether the pressure is too low. The pressure in your boiler should ideally be set at 1.5 bar. If it is less than one, your boiler will not work correctly.

A system leak recently bled radiators, or a failing component or seal can all contribute to low boiler pressure. You may start by looking for visual indicators of a leak, but you should not remove any casings from the boiler. We recommend contacting a Gas safe qualified engineer if you notice a leak. If you are unable to detect a leak, you may choose to repressurize your boiler.

3. There is no heat or hot water.

When your boiler stops doing what it was supposed to do – providing your house with heat and hot water – it may be quite irritating. Faulty motorized valves, damaged system diaphragms, airlocks, low pressure, or a broken thermostat can all contribute to this problem.

Check your pressure gauge to see if it is below 1 pressure to see if this problem is caused by low pressure. If that’s the case, it could need to be repressurized. If an issue with your thermostat is causing intermittent heating and hot water, check the device’s manufacturer documentation for a possible solution; if none can be identified, we recommend contacting your manufacturer for assistance.

If none of these alternatives work, we recommend contacting a certified engineer since issues like Boiler service or a broken motorized valve or a damaged diaphragm will require the help of a specialist.

4. Condensate Pipe That Has Frozen

This is a pretty common problem, especially during the winter months. The condensate pipe in your system is responsible for carrying condensate from your boiler to an exterior drain. During periods of cold weather, the condensate might freeze, resulting in a blockage. This is especially typical in homes when the condensate line is installed outside or in an unheated area like a garage. This problem might cause the condensate to back up into the boiler, causing the system to fail.

You can fix this problem on your own just watch a video on YouTube.

5. The Boiler Is Overheating

The boiler sometimes starts up OK, but then trips or shuts off. This can also occur because of low pressure. Check the pressure gauge if you’re having this difficulty. Re-pressurize the boiler if the needle falls below 1.

If the boiler pressure is adequate, air may be trapped in the radiators, which may be repaired by bleeding the radiators.

6: Strange Boiler Noise

A faint hum from the boiler is to be expected. If it makes a louder and odd sound, though, this might indicate a major problem.

Either a whistle or a gurgle will be heard from the boiler. When air is trapped in the pipes or the boiler itself, the boiler whistles. This problem can be resolved by bleeding the radiators. If the boiler is gurgling, it suggests there is a frozen pipe somewhere in the system that is preventing the water from flowing properly. It’s possible that you’ll need to hire a gas-safe engineer to discover the frozen pipe and resolve the issue. That should take care of the noise.

7: Problems with the Thermostat

When your thermostat keeps turning the heat on and off or loses accuracy, it’s time to replace it. The thermostat may be good, but you failed to do some basic checks, such as: 

 . Make sure that the thermostat is turned on.

. Check the settings (time and schedule) to ensure they are right.

Thermostat problems happen when the house gets warmer, and the thermostat won’t let the boiler heat the house at a greater temperature than what’s set. If that’s the case, increase the temperature by a new increment until you’re satisfied with the results.

If none of the previous solutions work, your thermostat is either damaged or losing its accuracy. Purchase a new one to solve this issue.

8. There is no pilot light.

A boiler’s pilot light is a little blue flame that keeps the burner burning. If it continues to run out, the boiler will become inefficient. This generally occurs when the thermocouple breaks, and the gas supply is disrupted.

If you’re trying to relight the light, ensure sure the gas supply isn’t imperfect. If the gas stopcock is turned on but the boiler isn’t receiving gas, it’s time to consult a professional. You may also manually relight the pilot light by following the directions in the handbook.

9. Radiators that do not heat up

It’s possible that the radiators aren’t heating up due to sludge or air in the system. Only the bottom of the radiator heats up at times. The radiator will need to be bled in such an instance. The method of bleeding the radiators is simple, and you won’t need the help of a heating specialist.

If some radiators are heating up while others are not, they may need to be balanced. To balance the radiators, adjust the valves on all the radiators. This ensures that each radiator receives enough hot water to function properly.

10: Hot water is ineffective, but central heating is (Or vice versa)

This is a common problem with older boilers. A diverter valve is frequently the source of the problem.

A diverter valve is in charge of purifying hot water before it reaches the taps. It’s also in charge of the heating. It directs the hot water to the taps first. It utilizes hot water to heat the house when the taps are turned off.

Due to sludge and debris, the valve becomes stuck over time. When this happens, the hot water supply or the heating system are both affected.

10 The Boiler Isn’t Working (No Power)

If your boiler won’t turn on because there’s no electricity to it, the problem is most likely electrical.

To begin, make sure the problem is limited to your boiler by examining the other of your home’s appliances. If they all appear to be operating and it’s only your boiler that’s the issue, it’s most likely a boiler issue.

A boiler that won’t switch on is usually due to a faulty PCB (circuit board), which must be replaced or repaired. Unfortunately, this is not cheap, and the parts alone will set you back a few hundred pounds.

12 The Water Isn’t Getting Hot Enough in The Boiler

You could have a boiler problem if the water coming out of your hot taps is lukewarm and won’t become any hotter. This problem might get significantly worse if it also affects your radiators.

A malfunction in a boiler component, such as a defective thermostat, a faulty heat exchanger, or a faulty diverter valve, might result in this.

Turn on your heating and see whether the water from your taps gets any hotter as a DIY remedy. If your radiators are operating regularly but aren’t getting heated while the water is flowing, your hot water thermistor may need to be replaced.

The great news is that it’s a reasonably inexpensive component, so it’s a smart place to start when troubleshooting your boiler.

If this fails, you should seek the help of a Gas Safe Engineer, who will be able to conduct more investigations, diagnose the problem, and quickly repair the boiler.


We hope this information has helped you in diagnosing and, hopefully, resolving your problem. If you want the services of a gas safe engineer for Emergency Boiler Repair Glasgow, please consult the Gas Safe register to find a local expert. If your boiler is nearing its end of life, contact All heating one. We provide finance options. Remember to use our Boiler Comparison tool to help you pick the best boiler for your needs.

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