Call an Engineer today on 01732 622990

Contact Us   Book A Job     Follow Us:
Your Heat > Boiler Installations  > Water From Your Combi Boiler Too Hot? This Could Be a Problem!
Scaled Heat Exchanger Hot water too hot water from Combi boiler too hot

Water From Your Combi Boiler Too Hot? This Could Be a Problem!

Combi Boiler Too Hot ?

You already know nothing can clean greasy dishes like hot water and detergent. However, hot water can also burn you (causing third-degree burns), which is why you should reduce the risk of scalding. We cannot tell you what the right and wrong temperature in your combi boiler is, but if you feel like it has gone wild recently, read on! We’ll explain why your combi boiler is producing water that’s too hot and how to solve this boiler water temperature issue. AHH…Combi Boiler Too Hot

A Little Bit More About Combi Boilers

Combi (combination) boilers are two units combined into one – a central heating unit and water heater. This type of boiler comes with no storage tank and water is heated directly from the mains supply. Most modern households use combi boilers for their design and compact size. However, that doesn’t mean your combi boiler won’t break down at some point.

Normally, your combi boiler produces hot water. Taking a hot bath after a long day can take away stress. But what should you do if the water has become way hotter than it used to be when you bought your brand new combi boiler? Should you risk suffering burns? Absolutely not.

Common Combi Boiler Water Temperature Problems

1. A Faulty Thermostat

You control the water and room temperature using a thermostat. The ideal temperature for most homes is somewhere around 21°. However, if your thermostat is faulty, it will display misreadings. The displayed temperature may seem pleasant, but your boiler may be incredibly hot if you touch it and the water coming out of it may be burning hot. Do not try to repair or replace a thermostat yourself but call an engineer instead.

2. Mismatched Temperature Dials

If your combi boiler has one temperature dial for central heating and another one for water heating, you may easily misuse these dials. Be careful which dial you use when changing the temperature. If your boiler seems too hot after you alter the temperature on the dials, turn it off and give it some time to cool down before turning it back on. Then, set the temperature a bit cooler than before to see if anything changes. If nothing changes, that means the dials are faulty or that there is an internal problem only a professional engineer can diagnose and solve.

3. Incorrect Flow Rate

A combi boiler needs a flow rate of 10 to 12 litres per minute. A too slow flow rate will make water heat more. If your boiler’s flow rate is under average, contact a professional engineer to set it to optimal. Sometimes, a major problem can mess up the flow rate, which is why it is so important to have a professional inspect the appliance.


Water in your combi boiler shouldn’t be too cold or too hot, and, if it is, that points to a bigger problem. Possible Scaled Heat exchanger. You can contact us anytime to discuss your boiler with one of our Gas Safe professionals, book a job, or get an instant quote on a new combi boiler that will be more energy-efficient and won’t have issues with unbalanced temperature.

Your Heat
No Comments

Leave a reply

× Chat with us!