Error 16 on Autoterm Air / Planar auxiliary heaters
Error 16, or 10 flashes on the PU-5 control panel, is one of the error messages that almost never appears. It is usually prevented by fixing other problems beforehand. A "real" error 16 is rare.
What does error 16 mean
When the heater is switched off, the fan keeps running for some time to cool the combustion chamber and heat exchanger. Error 16 appears exactly during this time and indicates that the cooling process is taking too long.
Cause
The cooling being too slow can of course have various causes. Such an error most likely occurs when the warm air outlet of the heater was placed too close to the intake, so that it sucks the heated air straight back in.
However, as mentioned above, error 16 is very rarely seen, because error 1 has usually been fixed beforehand - it also occurs because of warm air being drawn in and the resulting overheating, already while the heater is running. It is unlikely that in this case the heater only overheats while switching off.
Another cause would be a fan that runs too slowly or is completely blocked. But in this case, too, other error messages would very likely appear before the shutdown phase (for fan problems, e.g. error 27).
If error 16 occurs, you can therefore assume that a component is defective, primarily the fan speed sensor.
Conclusion
The heater does not cool down fast enough when switched off, probably caused by a defect in the fan speed sensor. In this case, please contact us using the form below. For other error messages, please take a look at our corresponding articles, which you will find in the yellow box, because in most cases removing the heater and sending it in is NOT necessary.
All error messages and what they mean
(Flash codes = PU-5 control panel)