If your boiler is switched on but your radiators remain cold, the problem could be low boiler pressure, trapped air in the radiators, a faulty thermostat or an internal boiler fault. Start by checking your boiler pressure, thermostat settings and heating controls. If your system is still not heating your home, read our Boiler Losing Pressure and Radiators Not Heating guides for further troubleshooting.
Cold radiators are commonly caused by trapped air, sludge buildup, low boiler pressure or a faulty circulation pump. If only one radiator is cold, bleeding it may solve the problem. If several radiators remain cold, the issue may require professional diagnosis. Our Radiators Not Heating guide explains the most common causes and solutions.
Yes. Low boiler pressure is one of the most common reasons a heating system stops working. Most boilers operate best between 1 and 1.5 bar when cold. If your pressure keeps dropping, there could be a leak or a fault within the heating system. Learn more in our Boiler Losing Pressure guide.
Heating systems can switch off because of overheating, faulty thermostats, low boiler pressure, circulation pump problems or internal boiler faults. If the problem happens repeatedly, it's important to have the system inspected before a small issue becomes a more expensive repair.
If your radiators are cold at the top but warm at the bottom, bleeding them is usually the first step to try. However, if multiple radiators stay cold or the problem returns frequently, there may be an issue with your boiler or central heating system that needs professional attention.
The cost depends on the cause of the fault and the parts required. Some heating problems can be resolved quickly, while others involve replacing components such as pumps, valves or thermostats. After diagnosing the issue, Keystone provides a clear quotation before any repair work begins, so you know exactly what to expect.
Yes. Keystone provides emergency heating and boiler repairs throughout London. Whether you've completely lost your heating, your boiler won't start or your radiators remain cold, our Gas Safe engineers can quickly diagnose the fault and recommend the most effective repair.
Yes. Our engineers repair and service many of the UK's leading boiler brands, including Worcester Bosch, Vaillant, Ideal, Baxi, Glow-worm, Viessmann, Alpha and Potterton. If your boiler displays an error code or has stopped heating your home, we can help identify the cause and recommend the appropriate repair.
Before booking an engineer, check that:
If you've completed these checks and your heating still isn't working, it's time to arrange a professional inspection.
Keystone specialises in boiler and central heating repairs across London. Our Gas Safe engineers diagnose faults efficiently, explain the problem clearly and provide transparent pricing before carrying out any work. Whether you have no heating, no hot water, a leaking boiler or recurring pressure problems, we're here to help restore your heating quickly and safely.
Before booking a repair, check that your boiler has power, the pressure gauge reads between 1 and 1.5 bar, the thermostat is set correctly, your stop valve is open and there are no obvious fault codes displayed. If these checks don't restore your hot water, professional diagnosis is recommended. This can help identify the fault quickly and avoid unnecessary downtime.