If you are looking to find out possible reasons why your boiler keeps shutting down when you turn it on then you are in the right place. In this article, we will discuss the possible causes. There are some issues that you can look into and fix yourself and there are some that require calling in a boiler engineer.
A potential issue could be short cycling if your boiler is turning on and off itself repeatedly.
What is short cycling and what causes it?
There is a water reservoir in your boiler system that is kept in the heat exchanger to keep the water hot for on demand use. When the water in a water reservoir starts cooling, a heat exchanger will start working to heat the water to a certain temperature and then it stops itself. The process keeps on repeating and may damage the heat exchanger.
Short cycling happens with over-sized boilers. It means when the boiler produces more steam then it can condense, it causes the boiler to lockout. Over-sized boilers are a thing of the past when they were not very efficient. Modern day boilers such as combi boilers are 90% efficient.
Your boiler pressure display will throw an error message if the pressure is either too low or it is too high. Boiler likes a steady 1.5 bar. Low pressure can be because of a leak in your system. Fix the leak and repressurise your boiler.
The boiler will shut itself off if the thermostat is not working or it has broken. Shutting down saves the boiler from overheating. Consider replacing the broken thermostat with a new one. It will help save money in the long term.
There can be other issues that might be leading to repeated shutting down of the boiler such as heat exchanger issues, frozen condensate, water pump.