Nothing is perfect but it is worrying when you see a fault code flash up on your boiler. We fit a range of boilers including the Baxi Platinum range. In this blog we would like to inform you what the E20 fault code means.
E20 means central heating NTC error
What does NTC mean?
NTC – Negative Temperature Coefficient. NTC thermistors are resistors with a negative temperature coefficient, which means that the resistance decreases with increasing temperature.
NTC Thermistors enable the boiler to log readings on resitance on the flow and return pipes. If you’re unsure what the flow is it’s the pipe allowing hot water to leave your boiler. The return is your pipe that lets water back into the boiler to be heated once it has gone round the system. (hope you’re following)
This type of thermistor don’t log a temperature but in turn send resistance readings to the printed circuit board (PCB). The printed circuit board then converts this reading to degrees. A the heat goes up in your boiler the resistance reading will then go down.
What does the NTC Thermistors protect
The NTC helps the printed circuit board detemine:
- Flow temperature isn’t increasing after start up
- Maximum temperature differential between the flow and return temperature has been reached
- The flow and return readings are reversed
What does the fault code mean?
Your boiler is controlled by a cental unit, which us techies call a printed circuit board. This helps the boiler to work basically for all you non techy people. the printed circuit board receives signals from sensors in the boiler but also helps the other parts of the boiler to operate, which include the NTS thermistors, water pressure and air pressure sensors.
IF your boiler displays E20 fault code it will more than likely it will lock itself out to stop the boiler from being unsafe or not working correctly. It is very unlikely that this will be unsafe, however it will protect the parts in your boiler from any further faults if the boiler isn’t working correctly. The famous saying of over compensating works everywhere! Please don’t worry about replacing your boiler as this can be fixed!
What causes this error
Boilers can have small vibrations and can on occasion work lose small parts including the NTC. If this isn’t working properly then the printed circuit board will be unable to send out the right signals. You may notice problems in the boiler like water not heating up properly and the boiler cutting out.
What to do if you see this error?
Call your boiler engineer (that’s us by the way!) We will check and test the NTC thermistor, which are very small parts and like any type of part they can stop working.
We test the NTC with flow and return and this helps us evaluate the problem, these tests also help us whether the boiler is getting any power. Once our tests are over we can identify if you need a the thermistor needs replacing. We won’t go into technical jargon but WILL be honest with our diagnosis
If your boiler is of a canny age as we say up North then we will be upfront and honest with you because it maybe cheaper to replace the FULL boiler