If Your Combi Boiler’s Hot Water Is Too Hot, Try This

It gets challenging to identify if your boiler is overheating the water. But if you feel that the water is getting too hot in too little time, you know there is an issue behind this. Boiled water has to be in a particular proportion where it finds the middle ground. It should not be too hot to result in severe burns while staying nowhere near the word cold.

Combi or combination boilers are a step towards modernising household appliances. These boilers are amalgamated with the central heating system so that the need for a storage tank can be evicted from the mix. However, if these boilers are misbehaving and the water temperature is absurd, you should get them checked as soon as possible. They can result in an explosion if they are not attended to properly.

Why Do Boilers Overheat?

There can be plenty of reasons for a boiler to start overheating the water. Faulty wiring or a circuit defect could cause this anomaly. Take a look at some of the most prominent reasons that cause this failure of water temperature.

Temperature Dial Frenzy

Many modern-day combi boilers have multiple dials to set the temperature of central heating and water differently. This arrangement confuses the users, and hence they end up changing the temperature of the wrong facility.

In such cases, you should opt to mark the dials with different annotations. However, if the water is still too warm after making the right amends, you must turn the entire system off to let it cool.

The situation should be normal after this, but you should look for technical support if it is still problematic. Your boiler may have an internal problem like faulty dials that might not be resolved without repair. You should always use trusted contacts for such repair issues.

Broken Thermostat

Thermostats are installed in these boilers so that the current temperature can be measured and shown. However, in many instances, these thermostats start misbehaving. You will always see a different temperature shining on the screen than the true one. It becomes a challenging problem to distinguish between hot and cold with respect to what is there on the screen.

In such cases, you should use professional help to resolve the problem. If you get involved in fixing the thermostat on your own, you might cause the whole system to shut down. You can also disrupt the wiring and the circuit board that can have horrific consequences.

Incorrect Flow Rate

If your boiler is not efficient enough to maintain a steady flow rate of around ten to twelve liters, it may cause the water to get overheated. Some boilers do turn faulty and have a very low flow rate. The entire heat is used to boil a minimal amount of water that makes it boiling hot. This minuscule quantity of water is efficient enough to cause high degree burns on your skin and several other issues.

These faults are not something that you set to repair on your own. You should always consult a professional in such matters that require expertise and are caused internally.

The Risks Of An Overheating Boiler

The modern appliances are equipped with safety and emergency protocols. In the event of a combi boiler overheating, most companies put a switch that turns the unit off. However, if your unit is not equipped with such technology, the unit’s internal elements might catch fire. These burning fragments are responsible for releasing toxic smoke that can cause various respiratory disorders.

In the worst possible event, the entire central heating system can explode due to the work of a circuit failure. It would help if you always kept your appliances in check to avoid such contingencies. If your boiler needs some repair work, it should be done on high priority.

Common Causes Of Combi Boiler Overheating

Except for the few reasons mentioned above, there are various other causes for the combi boilers to turn rogue and get extra hot. These issues should be catered to earliest so that the core problems can be uprooted without any damage.

Here is a list of some of these causes:

  • Limescale build-up on the heat exchanger
  • Blockage in the system
  • Faulty pump
  • Thermistor issue

If your boiler is showing the signs of any of these, you must get it checked immediately for repair assistance.

How To Prevent Your Boiler Overheating

The most important thing that you have to do is to ensure that the water supply is shut. It is imperative to shut the water supply; otherwise, cold water will keep running to the overheated unit. Once this happens, all the cold water will be converted into steam instantly. 

The collected steam can rise to extreme levels and cause the pressure to flux. After making sure that no more water is getting flown, you should immediately contact an engineer registered with the gas safe. They are the right people who are aware enough to work and pinpoint the issue for you.

Limescale Build Up On The Heat Exchanger

The basic functioning of the heat exchanger revolves around releasing hot gas on water. After coming in contact with the hot gas, this water is circulated to ensure the heating in every room. 

Continuous usage along with the time factor can cause limescale to build upon it, which is responsible for obstruction in the flow of water. This entire process of limescale formation is popularly known as kettling. The reason behind this name is the kettle like sounds that are heard when there is limescale present on the exchanger.

If you notice any of these sounds, you should contact an engineer. A total overhaul incorporating complete flushing of the system will get rid of any limescale that might be present.

Blockage In The System

If your central heating system is making unusual noises, it is an exact situation of blocked pathways. These blockages are usually caused due to limescale, sludge, and many other debris items that might be present.

These blockages cause the radiators to underperform, and thus needs to be cleaned again for better performance. You must inform an engineer about this issue so that they can conduct a power flush. Powerflushing is the process in which a complete cleansing procedure is used. 

This procedure clears the entire central heating system so that the water can flow freely to the radiators. This will help the radiators to work optimally.

Faulty Pump

The pump is responsible for pumping the hot water throughout the central heating system. If the pump goes bad, all the boiling water will stay at its initial position. This malfunction will result in the same water getting overheated.

You should contact a heat engineer to ascertain whether a new pump will be needed or not.

Thermostat Issue

As mentioned above, a thermostat is used to measure the temperatures of the boiler so that the necessary adjustments can be made. If the thermistor turns faulty, you will be unaware of the real situation until an engineer comes and fixes the problem.

Is An Overheating Boiler Dangerous

An overheating boiler is extremely dangerous as it might result in an explosion. It would be best if you always put these repairs on the top of your priority list. They are extremely important for the overall setting of your house.

How To Prevent Your Boiler From Overheating

Blockage issues are the most common cause for these boilers to overheat. These blockage troubles can be uprooted by installing a magnetic filter. The magnetic filter is capable of catching any debris before it gets deposited.

Installing a magnetic filter has become a common precautionary practice. It ensures a longer life for your entire central heating system. However, if you already have a faulty boiler, you should consider buying a new one. The cost of constant repairs will add up more than the price of a new boiler.

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Frequently Asked Questions

How do I adjust the temperature on my combi boiler?

The medium to adjust the temperature on your combi boiler may differ from the technology that was used to create it. Some boilers have knobs and dials, while some have digital panels too. Your boiler might have a single dial for both the operations or even a combined one.

How hot is too hot for tap water?

The water flowing from your tap should not be more than 49 degrees Celsius (120 Fahrenheit). If the temperature exceeds this mark, it can cause severe damage to the human skin.

What temperature should the hot water be on a combi boiler?

It is effortless and convenient to change the temperature on these appliances. The ideal temperature that you should stick to is 75 Degrees Celsius for the radiators and 60 degrees celsius for the water that is flowing inside. It is neither too high nor too low

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