Why is my heating not working but I have hot water?

If you've got hot water, but no central heating then there are more issues it could be if it's not the thermostat or the boiler pressure. Common reasons for this particular fault are broken diaphragms and airlocks, or a motorised valve failing.

Why will my heating not come on?

If your heating system will not turn on, the first thing you should do is check the thermostat. The thermostat's battery may have gone bad, causing it to power off. If your thermostat is hardwired, a power surge, brownout, or brief power outage may have caused the thermostat to lose its settings.

Why are my radiators cold when the heating is on?

Why is one radiator cold when the heating is on? One cold radiator usually indicates that either there is air in the system or there is a stuck valve within that radiator. The thermostatic radiator valve (TRV), like the one pictured below, controls the flow of hot water to the radiator.

Why is my central heating boiler not firing up?

A boiler might not ignite due to various possible reasons – insufficient pressure, blockage in the burner, faulty valves, frozen pipes etc. Sometimes, you can fix the problem on your own. In other cases, you don't have any choice but to call an engineer.

Why is my boiler heating water but not radiators?

If your boiler works but the radiators are not heating up, then likely cause could be a faulty boiler pump or your central heating controls. If your boiler works but the radiators are cold, check that the thermostat or timer is working correctly.

What To Do If Your Hot Water or Central Heating Isn't Working

Why are none of my radiators not getting hot?

Check for Trapped Air and Bleed Your Radiators

If just one (or a few) of your radiators aren't heating up, the most common reason for this is trapped air. If you've just turned the heating back on after the summer, air can become trapped in your radiators, causing them to be warm at the bottom but cold at the top.

Should you bleed radiators with heating on or off?

Should I be bleeding radiators hot or cold? Always make sure your central heating system (your boiler) is turned off and your radiators are cold before attempting to bleed them. When turned on, your radiators contain hot water, and you could be at risk of scalding yourself if you bleed them at this time.

Do you let all the water out when bleeding a radiator?

Bleeding your radiators isn't the same as flushing a system - you're not removing the water, just letting the air out. It's a process that takes just a few minutes, but could improve the efficiency of your heating system and make your home a little toastier.

Do you bleed radiators when hot or cold?

You must not bleed a radiator when the heating is turned on as it may be too hot to touch and hot water could spray out of it. Ensure the heating is turned off before you begin bleeding a radiator. Letting out air when the pump is running will only draw more air into the system from elsewhere.

Why is my thermostat not calling for heat?

The most common reasons for such a problem are a dirty filter, thermostat malfunction, pilot ignitor, wrong settings, or low battery issue. In such a case, all you would have to do is clean the device, double-check the thermostat settings, or replace the batteries.

How do I know if my radiators need bleeding?

Can bleeding radiators affect boiler?

Yes. During the process of bleeding radiators, air is released from within them, which in turn reduces the pressure in your boiler system.

Why does my heating only work when hot water is on?

The valve itself is actually opening hence the heating system is getting hot when the hot water is on but the boiler is only fired up when the hot water motorised valve is open, the boiler should fire up if either valve is open. Hope this helps-Kevin.

Why are my radiators not turning on?

This is an indication that you have debris, a blockage, or most likely, sludge, which has accumulated in the radiator. Hot water is not able to circulate because of the build-up at the bottom of the radiator. The most efficient and safest way to deal with this problem is to seek professional help.

How do I reset my boiler?

How do I know if my central heating thermostat is broken?

Do all boilers have a reset button?

All boilers have a reset button but its location and how to use it varies from model to model. If you can't see the button, then check the manual that came with your boiler. This should also explain how to reset your boiler.

Do I need to press the reset button on my boiler?

You will only need to press the reset button for three seconds before the boiler resets and the display screen should change. It's recommended to always check your Vaillant boiler manual, as some models may have slightly different reset instructions.

Where is the thermostat on my boiler?

Heat-only boilers come with a central heating thermostat (which you can find on the main boiler unit) and a hot water cylinder thermostat (which you can find on the cylinder itself, near the bottom). Both thermostats look like small dials with a range of temperature options in a circle.

What are the signs of a clogged radiator?

How do you diagnose radiator problems?

How do I unclog my radiator?

Disconnect the top and bottom hoses from the radiator and attach a garden hose to the top hole. Turn on the hose to clear the clog. Put everything back together, add fresh coolant to the radiator, and fire up the car. Your car should be running smoothly now if a clog was indeed the problem.