A boiler is a system used to raise and lower the temperature of water or gas in a boiler. It allows for the boiler to be less susceptible to problems relating to not being at the right temperature and to provide you with a reliable heating source during the winter months when it can be very cold outside. The amount of power that is required to heat up the water in your boiler will depend on the size of your boiler and your home.
A general rule of thumb to use is that if you have a single radiator heating system and boiler then it can only use one cubic meter of hot water per minute, regardless of the temperature. As the radiator heats up the water in your boiler it pulls the hot water through radiators and out of the boiler unit. This process continues as the water reaches the appropriate temperature and passes through the pipe. The reason that this happens is because the temperature of the water at the end of the pipe is higher than the temperature at the beginning. If your boiler had a single radiator, heated water would pass through at a constant temperature and the radiators would not be necessary and so more power would have to be expended to heat up the water.
It is important that if you find your radiators are not heating up as much as they used to, you might want to contact a Boiler Repair Gloucester such as HPR Services to try and find out whether the issue might be with your overall heating system and boiler function.