Are you experiencing issues with your Boiler? Here are common issues and solutions for each Boiler and preventive measures to keep your Boiler running smoothly year-round.
The Boiler is an essential appliance in households, providing hot water and heating to keep your home comfortable throughout the year.
There are three main types of Boilers Combi, System, and heat-only Boilers.
All do a fantastic job, working daily to serve you and your family. They do, however, from time to time develop issues.
Here are common issues and solutions for each type of Boiler.
Please note: A certified Gas Engineer must undertake some of the solutions listed here. Never attempt Boiler Repairs yourself.
Common Combi Boiler Issues & Solutions
A Combi (combination) Boiler provides both central heating and hot water on-demand without needing a separate hot water storage cylinder or a cold-water storage tank.
This makes it a popular choice for modern households, particularly in homes with limited space.
Some common combi boiler problems and their solutions include:
Low Water Pressure
Causes: Incorrect pressure setting, leaks in the system, a faulty pressure relief valve, or air trapped in the system.
Solutions: Repressurise Boiler to 1.5 bar. If the pressure still drops inspect your Boiler and pipes for leaks, and if necessary, replace the faulty valve. Bleed the radiators to release trapped air and restore proper water pressure.
No Hot Water Or Heating
Causes: A broken diverter valve, a faulty thermostat, or low water pressure.
Solutions: Replace the diverter valve if it’s not functioning properly, ensure the thermostat is set correctly, and check for any issues causing low water pressure.
Pilot Light Keeps Blowing Out
Causes: Blocked or damaged burners, a malfunctioning ignition lead, or a faulty thermocouple.
Solutions: Clean the burners, replace the ignition lead, or install a new thermocouple.
Leaking Or Dripping
Causes: Damaged seals, a cracked heat exchanger, or a faulty pressure relief valve.
Solutions: Replace damaged seals, repair or replace the heat exchanger, and install a new pressure relief valve if necessary.
Kettling (Boiling Kettle Noises)
Causes: Limescale buildup or trapped air within the system.
Solutions: Flush the system to remove limescale and debris and bleed the radiators to release the trapped air.
Common System Boiler Issues & Solutions
A System Boiler implements a separate pressurised hot water storage cylinder to provide hot water. This type of Boiler is suitable for homes with a higher demand for hot water or multiple bathrooms.
Some common issues with System Boilers include
Causes: A faulty thermostat, a malfunctioning pump, or a blocked heat exchanger.
Solutions: Replace the thermostat, repair or replace the pump, and clean the heat exchanger to ensure proper heat transfer.
Inadequate Water Circulation
Causes: A blocked or damaged pump, air trapped in the system, or radiator sludge buildup.
Radiator Cold Spots
Causes: Air trapped in the radiators, sludge buildup, or an unbalanced radiator system.
Solutions: Bleed the radiators, flush the system, and balance the radiators by adjusting the lockshield valves on each radiator.
Expansion Vessel Problems
Causes: A ruptured diaphragm, a faulty pressure relief valve, or incorrect air pressure in the vessel.
Solutions: Replace the diaphragm, install a new pressure relief valve, or adjust the air pressure in the expansion vessel according to the manufacturer’s instructions.
Causes: A seized pump motor, a blocked impeller, or a blown pump capacitor.
Solutions: Replace the pump motor, clean the impeller, or replace the pump capacitor as needed.
Common Heat-Only Boiler Issues & Solutions
A Heat-only Boiler, also known as a Regular, Conventional, or Traditional Boiler, uses a separate hot-water storage cylinder and cold-water storage tank, typically located in the loft.
Heat-only boilers indirectly use the hot water cylinder to provide central heating and hot water.
These boilers are commonly found in older homes and are well-suited for properties with multiple bathrooms and a higher demand for hot water.
Here are some common heat-only boiler problems and their solutions:
The Pilot Light Regularly Blows Out
Causes: A faulty thermocouple, a blocked or dirty pilot light.
Solutions: Replace the thermocouple, and clean the pilot light.
Causes: Low water pressure, a faulty thermostat, or a malfunctioning pump.
Solutions: Check for leaks and address any issues causing low water pressure, replace the thermostat, or repair or replace the pump as needed.
Causes: Air trapped in the system, sludge buildup in the radiators, or an unbalanced system.
Solutions: Bleed the radiators, flush the system to remove sludge and debris, and balance the radiators by adjusting the lockshield valves.
Causes: Limescale buildup, air trapped in the system, or a malfunctioning pump.
Solutions: Flush the system to remove the limescale, bleed the radiators to release trapped air, or repair or replace the pump as necessary.
Boiler Pressure Fluctuations
Causes: Leaks in the system, a faulty pressure relief valve, or a malfunctioning expansion vessel.
Solutions: Inspect your Boiler and pipes for leaks, replace the faulty pressure relief valve, or repair or replace the expansion vessel as needed.
Preventive Measures & Maintenance Tips
To keep your Boiler running efficiently and prevent issues, consider the following maintenance tips:
- Regular servicing: Have your Boiler serviced annually by a Gas Safe Registered engineer to ensure it’s in good working order and to address any potential issues. Annual servicing is the best protection you can give your Boiler.
- Inspecting and cleaning the system: Regularly check your Boiler for signs of wear, leaks, or damage.
- Maintaining proper water pressure: Monitor your Boiler’s water pressure and address any issues causing pressure fluctuations, such as leaks or air trapped in the system.
- Checking safety devices and controls: Ensure that all safety devices, such as the pressure relief valve and thermostat, are working correctly. An engineer will do this during Servicing.
- Ensuring proper ventilation: Get an engineer to verify your Boiler has adequate ventilation.
When to Call A Gas Engineer
While the homeowner can address some Boiler issues, often professional help is needed.
While you can bleed your radiators and repressurise your Boiler yourself (if you’re confident to do so), always hire a Gas Safe Registered Engineer to inspect and repair your Boiler and Central Heating System.
If you live in the Essex area and are experiencing Boiler issues, we can help you. Click Here To Contact Us.