Help! I have hot water, but no heating!

Experiencing hot water but no heating in your home can be frustrating, especially during the colder months. This issue is common in households with combi boilers, and understanding the possible reasons and solutions can help you resolve it quickly.

Can you have hot water without heating?

Yes, it is possible to have hot water without heating. This situation can occur when your boiler’s hot water function is working correctly, but there is an issue with the central heating system. Since combi boilers are designed to provide both hot water and heating, a malfunction in one system does not necessarily affect the other.

Why is my boiler making hot water but not heating my home?

Several reasons might explain why your boiler is producing hot water but not heating your home. Here are some common causes:

1. Thermostat Issues: If your thermostat is not set correctly or is malfunctioning, it can prevent the boiler from activating the heating. Check the settings and replace the batteries if necessary.
2. Faulty Diverter Valve: The diverter valve controls the flow of hot water between the heating system and the taps. If it’s stuck or faulty, it might not direct hot water to your radiators.
3. Low Boiler Pressure: Boilers require a certain pressure to operate efficiently. If the pressure is too low, it can prevent the heating system from working. Check the pressure gauge and refill the boiler if needed.
4. Airlocks in the System: Air trapped in the pipes can block the flow of hot water to the radiators. Bleeding your radiators can release the trapped air and restore the heating function.
5. Sludge Build-Up: Over time, sludge can accumulate in the heating system, causing blockages and reducing efficiency. A power flush can help clean the system.
6. Faulty Pump: The pump is responsible for circulating hot water around the heating system. If it’s not working properly, hot water won’t reach the radiators.

Common, simple fixes for your boiler

Before calling a professional, there are some simple checks and fixes you can try:

1. Check the Thermostat: Ensure that the thermostat is set to the desired temperature and is functioning correctly. Replace the batteries if needed.
2. Reset the Boiler: Sometimes, resetting the boiler can resolve minor issues. Refer to your boiler manual for instructions on how to reset it.
3. Bleed the Radiators: Use a radiator key to release any trapped air in the radiators. This can improve the flow of hot water and increase heating efficiency.
4. Refill the Boiler Pressure: If the pressure gauge indicates low pressure, follow the instructions in your boiler manual to refill it to the recommended level.
5. Inspect the Diverter Valve: If you suspect the diverter valve is faulty, it might require professional attention, but you can check if it’s stuck and try to free it.

Common faults with your boiler

Understanding common boiler faults can help you identify and address issues promptly:

1. No Pilot Light: If the pilot light is out, the boiler won’t produce heat. Relighting the pilot light can resolve this.
2. Faulty Thermocouple: This component senses when the pilot light is on. If it’s faulty, it might cut off the gas supply even if the pilot light is lit.
3. Frozen Condensate Pipe: In cold weather, the condensate pipe can freeze, causing the boiler to shut down. Thawing the pipe with warm water can fix this.
4. Electrical Issues: Faulty wiring or blown fuses can prevent the boiler from operating. Check the electrical connections and replace fuses if necessary.

What should I do?

If you’ve tried the common fixes and your boiler is still not heating your home, it may be time to call a professional. A qualified heating engineer can diagnose and repair more complex issues, ensuring your boiler operates safely and efficiently. Regular maintenance and servicing can also prevent many common boiler problems, so consider scheduling annual check-ups to keep your heating system in top condition.