5 Common Winter Boiler Problems and How to Fix Them

During winter, when the temperature plummets, having a warm home is vital. Being able to snuggle up inside with the view of bleak weather conditions outdoors is the epitome of cosy winter days. However, without functioning central heating and hot water, this season is unbearable.

 

If you’re struggling to heat your house sufficiently or your showers are running cold, there may be a problem with your combi boiler. Ignoring this potential issue won’t just leave your home uncomfortably cold, it could also increase your energy bills and even be dangerous.

 

1) Radiators aren’t heating up

There are many reasons why a radiator might not be heating up properly, but to determine the cause you need to identify the patterns. 

 

For example, if there’s just one radiator functioning incorrectly, there may be an issue with the valve. Whereas if all the radiators are cold at the bottom, they may have developed sludge inside, which will require a professional power flush. Alternatively, if they have cold patches, are cold at the top, or take a while to heat up, you may need to bleed the radiators.

 

It’s a common mistake to try to combat this problem by turning up the thermostat or keeping the central heating on for longer, but this will only increase energy costs. Overlooking these issues can potentially lead to a boiler breakdown so ensure you find a solution.

 

2) Loud radiator noises

Radiators shouldn’t be noisy, so if strange sounds occur, it’s usually a sign of faults. A gurgling noise is often a symptom of air becoming trapped in the system, which is resolved by bleeding the radiators.

This process entails inserting the radiator bleed key into the bleed valve, when the radiators are cold, and turning it anti-clockwise until hearing a hissing noise. When air stops seeping out, and water begins to trickle, twist the key clockwise to close the valve.

 

If your radiators make banging noises, your boiler might be kettling, which is when limescale develops and blocks the pipes leading to the radiators. Hiring a professional to power flush the system should resolve this issue.

 

3) Boiler leaks

If your boiler is leaking water, it can cause severe damage to the appliance and your home, so don’t hesitate to contact a qualified engineer to inspect it. Although you shouldn’t attempt to repair it yourself, turn the boiler off and clean any leakage.

 

Possible causes of boiler leaks include:

the boiler pressure or water temperature becoming too high

a build-up of corrosion

loose joints

an incorrect boiler installation

 

However, boiler leaks can be a sign that the appliance is due for a boiler replacement. The online boiler installation company, BOXT, has a 'find a boiler' tool that advises users on the type of boiler most suitable for their property.

4) Low boiler pressure

The boiler pressure gauge, which is often found on the boiler’s control panel, should ideally be between 1 and 2 bars. If the number has dipped below that, the pressure is too low and can cause hot water to stop working, and your radiators to stop heating efficiently.

 

After turning the boiler off and waiting for it to cool, repressurise the boiler by opening the valves with a filling loop to let more water into the system until the pressure reaches 1.5 bars. Once you’ve removed the filling loop, turn the boiler back on and check the pressure level.

 

5) Boiler isn’t responding to thermostat

If your boiler isn’t meeting the temperature settings on the thermostat, the controls may be faulty. Before contacting the manufacturer, replace the thermostat’s batteries, if it’s battery-controlled, to ensure it has enough power.

 

Next, if you’ve set the thermostat below 21 degrees, increase it, as this can sometimes prevent the central heating from turning on at all.

 

If the boiler still isn’t responding to the controls, check whether you need to relocate the thermostat. When placed too close to a draught or radiator, a thermostat may inaccurately measure the room’s temperature.

 

Your thermostat may need replacing if it still doesn’t function after these changes.

 

Always check your boiler manual before addressing an issue. Most common boiler problems are often easily solved but can sometimes be a sign of a serious fault. If you're unsure what the issue is or how to address it, contact a Gas Safe registered engineer to check the appliance.