If your hot water works but your radiators stay cold, possible causes include incorrect heating settings, a thermostat that is not requesting heat, or a faulty valve or control. It does not automatically mean you need a new boiler. The cause depends on your heating system and needs to be identified before any parts are replaced. worcester-bosch.co.uk
For homeowners in Grays, Thurrock and Upminster, this can become noticeable when the heating goes back on after summer. Your taps may have supplied hot water for months without you testing the radiator circuit.
Here are the checks you can make and when to arrange professional help.
What should I check first?
Start with the controls you normally use, without opening the boiler or removing any electrical covers.
Check that your thermostat is set above the current room temperature and that the heating timer is showing the correct time. A heating schedule will not request warmth outside its programmed periods, even though hot water may still be available.
Look at the boiler display and note any fault code. If the manufacturer’s instructions recommend a reset for that particular fault, follow them. If the fault returns, arrange an inspection instead of repeatedly resetting the appliance. Boiler repairs should be carried out by a Gas Safe registered engineer. Worcester Bosch
Before calling, make a note of:
- Whether every radiator is cold or only certain rooms.
- Whether the boiler responds when you turn up the thermostat.
- Any message or error code on the display.
- When the heating last worked properly.
These details help explain the problem clearly.
Could the thermostat or timer be responsible?
Yes. Hot water working does not prove that the heating controls are working correctly.
The thermostat and programmer tell the system when heating is needed. A settings issue or a fault in the controls can prevent that request from reaching the boiler.
If changing the normal settings makes no difference, an engineer can check the controls and their connections. Avoid trying to test wiring yourself.
Could it be a diverter valve or motorised valve?
A valve fault is another possibility, although the arrangement varies between systems.
Many combi boilers use a diverter valve to direct heat towards hot water or the radiators. Systems with a separate hot water cylinder may use motorised valves to control different circuits.
If a valve fails to operate correctly, one part of the system may work while another does not. Similar symptoms can also come from controls or other components, so this is a diagnosis to confirm, rather than a reason to order a replacement valve. worcester-bosch.co.uk
Should I check the boiler pressure?
If your system has a pressure gauge, compare its reading with the range specified in your boiler manual.
Low pressure can affect heating operation, but it should not be assumed to explain every case where hot water still works. If the pressure repeatedly falls, the underlying cause needs investigating.
Our guide to why boiler pressure keeps dropping explains the warning signs and when to seek help. gasureplumbingandheating.co.uk
Do I need a new boiler?
Not necessarily. A problem with the heating controls or a valve may be repairable.
The sensible first step is to identify the fault. That gives you a basis for comparing the repair cost with replacement, taking the boiler’s age and condition into account.
Who can help with heating repairs in Grays?
Gasure Plumbing & Heating provides central heating and radiator repairs in Grays and the surrounding area.
If your hot water is working but the heating will not come on, call 07776 153 815 or contact Gasure to arrange an inspection. Explain what you have checked and mention any displayed fault code.