Heating Repairs:
Fixing Boilers the Right Way

Repair or Replace?

When something goes wrong with your heating or hot water, replacing the boiler isn’t always the answer. Many faults can be repaired safely and reliably. This can save you the cost and hassle of getting a new boiler.

Some engineers go straight to recommending a replacement, especially with older boilers. I take a different approach. I’ll always look for a sensible repair first. I’ll only suggest a new boiler if it’s unsafe, doesn’t meet today’s standards, or would clearly cost more to fix than replace.

I always prefer to repair where possible. If it can be fixed, I’ll repair it quickly, safely, and for a fair price.

Simple Fixes You Can Try First

Not every heating problem needs a callout. Some issues can be sorted with a quick check or adjustment that you’re allowed to do yourself:

• Repressurising the boiler
• Bleeding a radiator
• Checking the batteries in your thermostat or heating controls
• Making sure the room thermostat is turned up
• Checking the boiler thermostat is set to the right temperature
• Checking the radiator valves are open
• Checking the heating hasn’t been turned off by accident

If you’re not sure, just give me a call. I’m always happy to offer free advice over the phone. If it’s something simple, I can talk you through it safely. If you’d prefer, I can explain it to a family member or friend who’s more confident with practical jobs.

Common Heating and Boiler Faults

Here are some of the most common problems I see with boilers and heating systems. These examples may help you understand what’s going on if your boiler or radiators aren’t working as they should. Every home is different, so if you’re unsure just get in touch and I’ll be happy to take a look.

Boiler Breakdown

If your boiler keeps switching off or needs resetting again and again, then something isn’t right. It’s a sign the boiler needs checking by a qualified Gas Safe engineer. Write down any error codes that appear on the display. These codes help me find the problem faster.

If your boiler is acting in a strange way, taking a short video on your phone can also help. A quick look at the video often saves time when I come to diagnose the fault.

Boiler Making Strange Noises

If your boiler is making strange noises, it could be caused by air in the system, low pressure, or sludge in the pipes. Sometimes the pump or fan can also make noises when they’re not working properly.

You can try checking the system pressure or bleeding your radiators. These are things you can safely do yourself. If the noise carries on, it’s best to get it checked by a Gas Safe registered engineer.

If you can, take a short video of the noise. It gives me a better idea of what’s happening before I arrive, which can save time when fixing it.

Boiler Switching Itself Off

If your boiler keeps switching itself off, there could be a few causes. It might be a weak or faulty pump, or corrosion in the system that is stopping the water from flowing properly.

In very cold weather, the problem could also be caused by incorrect boiler settings. This can affect how efficiently the gas burns. I can check the setup and make any necessary gas valve adjustments to ensure safe, proper combustion.

Another common cause is a frozen condensate pipe, especially if the pipe runs outside. A temporary fix is to carefully pour warm water over the frozen pipe. For a long-term solution, fitting a larger, insulated pipe can prevent it from freezing again.

Incorrect Room Temperature

If your home isn’t staying at the right temperature, there are a few possible reasons. Sometimes it’s a simple fix, like changing the batteries in your thermostat (see the “Simple Fixes” section above).

If some radiators aren’t heating evenly or certain rooms feel colder than others, your system might need balancing. Balancing makes sure hot water flows evenly to every radiator, so each room reaches the right temperature.

Another common cause is sludge build-up, which can reduce water flow and leave some radiators cooler than others. I can check your system and get it heating evenly again.

Leaking Radiator

A leaking radiator might seem like a small problem, but it can cause bigger problems later, especially on a pressurised system. Even a slow drip can lower boiler pressure and stop the heating from working properly.

Most leaks are simple to fix, but it’s best to sort them quickly to avoid corrosion, water damage, or costly repairs in the future. If you notice damp patches, rust, or drops forming around a valve or joint, then it’s a good idea to get it checked as soon as possible.

Cold Radiators

If your radiators aren’t getting properly warm, sometimes it’s a simple fix, like bleeding radiators or repressurising your boiler. I mentioned these “simple fixes” earlier on this page. I’m always happy to give advice over the phone, and I don’t charge for phone calls.

If that doesn’t solve the problem, it could be sludge build-up inside the system. Sludge is a mix of rust and debris that collects over time and stops hot water circulating properly. Before you pay for a full power flush, I can add a cleaner to your system, leave it to circulate for a week, then drain it to remove most of the sludge.

Another possible cause is corrosion, especially if only one radiator is cold. In that case, I can remove the radiator and flush it outdoors.

If none of these are the issue, the problem may be the circulating pump, which moves hot water around the system. If the pump is weak or has failed, I can replace it to get your heating working properly again.

Water That Runs Hot and Cold

If your combi boiler’s hot water keeps running hot and cold, it could be a sign that your system needs cleaning or maintenance. Sludge and rust can build up inside your heating system and block the heat exchanger (the part of your boiler that transfers heat to the water).

The good news is that this can usually be fixed without replacing the boiler. I can clean or flush the system and fit a magnetic filter to help stop the problem coming back. The magnet collects small metal particles before they reach your boiler, protecting it from damage.

I can also add a corrosion inhibitor to the heating system water. This helps prevent new sludge from forming, keeps your radiators heating properly, and improves your boiler’s efficiency.

What Causes Sludge in Central Heating Systems?

Over time, radiators and pipework can start to rust on the inside. This rust mixes with tiny metal bits and turns into a thick, dark sludge. The sludge moves around the system and often settles at the bottom of your radiators.

When air gets into the heating system through small leaks, the air speeds up the corrosion process, making more rust and sludge. When this happens, radiators can stay cold at the bottom, make noise, and your heating may not work as well. In bad cases, it can even harm your boiler or pump.

The best way to prevent sludge is by keeping your system looked after. Adding a corrosion inhibitor helps slow down rust, and fitting a magnetic filter catches metal particles before they reach your boiler. If sludge has already built up, a chemical clean or professional power flush can remove it and get your heating working properly again.

If your boiler keeps cutting out or your hot water temperature goes up and down, it may be a sign of sludge build-up. Feel free to get in touch for me to take a look.

Get In Touch

If you’re having trouble with your heating or hot water, I’ll always aim to get it running safely as soon as possible. I operate from Bacup in Lancashire and work across the North West, including Cheshire, Greater Manchester, Liverpool and Lancashire. I’m always happy to offer free advice over the phone. You’ll get honest guidance, straightforward explanations, and a repair-first approach. If something doesn’t seem right with your boiler or radiators, just get in touch and I’ll be happy to hear from you.