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Combi Boiler Troubleshooting

What to do When Your Combi Boiler Hot Water Goes Cold?

Your combi boiler is supposed to provide you with an endless stream of hot water, but sometimes that doesn’t happen. Perhaps you noticed that the hot water turned cold while you were in the shower or that the tap was giving you lukewarm water instead of the usual hot. This can be quite frustrating, especially if you’re in a rush. If you’re experiencing hot water issues with your combi boiler, don’t panic. There are several factors that can cause this problem, but with a little troubleshooting, you can often fix the issue yourself. In this article, we’ll discuss why your combi boiler might be giving you cold water and what you can do to fix it.

Troubleshooting Why Your Combi Boiler Hot Water Goes Cold

1. Check the Pressure

The first thing you should do if your combi boiler hot water goes cold is check the pressure. If the pressure drops below 1 bar, the boiler will automatically shut off the heating to protect itself from damage. You can check the pressure gauge on your boiler to see if it’s below 1 bar. If it is, you’ll need to re-pressurize the system. This can often be done by opening the filling loop valve and adding water until the pressure reaches 1.5 bar. Check your manufacturer’s instruction manual for specific instructions.

2. Check the Thermostat

Another reason your combi boiler might be giving you cold water is due to a faulty thermostat. The thermostat is responsible for regulating the temperature of the water and turning the boiler on and off to maintain the desired temperature. If the thermostat is faulty, it may be turning the boiler off prematurely, causing the water to cool down quickly. To check if the thermostat is the problem, turn up the temperature on the thermostat and see if the boiler kicks in. If it doesn’t, you may need to replace the thermostat.

3. Check the Pilot Light

If your combi boiler hot water goes cold, it’s possible that the pilot light has gone out. Without the pilot light, the boiler won’t be able to ignite and heat up the water. Checking the pilot light is easy. Locate the pilot light on your boiler and see if it’s lit. If it’s not, follow the instructions in your manufacturer’s manual to relight it. Make sure to follow the safety instructions carefully.

4. Check for Airlocks

Airlocks can also cause issues with your hot water. Airlocks occur when air gets trapped in the system, preventing the water from flowing through the pipes. This can cause a drop in water pressure and may even cause the boiler to shut off. To fix an airlock, you’ll need to bleed your radiators. This can be done by loosening the valve on the radiator until all the air escapes.

4. Call a Professional

If you’ve tried all these troubleshooting techniques and your combi boiler is still not producing hot water, it’s time to call in a professional. A qualified heating engineer will be able to diagnose the issue and make the necessary repairs. Don’t attempt to fix the problem yourself if you’re not confident in your abilities. Boiler repair can be dangerous and should only be attempted by someone with the proper training.

Boiler Upgrade/Repair

If the above troubleshooting tips don’t work, then you may need to replace or repair your combi boiler. This often requires a qualified engineer to assess the situation and make any necessary repairs. It’s important to remember that old or faulty boilers will not be as efficient as a newer model, so replacing it with a more modern system could save you money in the long run.

In addition, if you’re having regular issues with your combi boiler, then it may be time to upgrade to a newer model. Newer boilers are more efficient and can provide better performance than older models. They also require less maintenance in the long term, meaning fewer visits from an engineer and lower energy bills.

The UK government is providing grants to help people upgrade their boilers. This could be a great way to get a new combi boiler and benefit from the improved performance. You can apply for free boiler grants, if you are eligible. Be sure to check out the government’s website for more information on eligibility and how you can apply for a grant.

Hot water issues with your combi boiler can be frustrating, but they’re often easily fixed. By checking the pressure, thermostat, pilot light, and looking for airlocks, you can often diagnose and repair the issue yourself. If you’re not confident in your abilities, don’t hesitate to call a professional. With a little bit of troubleshooting, you’ll be back to enjoying hot showers in no time.

Athira Harish