We have a Bosch WTR8500AU Series 6 8kg heat pump dryer and noticed that there is water pooling in the base tray under the heat exchanger. I noticed it after cleaning the base unit as per pages 40-43 in the manual.
We have the drain hose connected.
Is this normal? Or should I log a fault with Bosch?
It's the heat exchanger - if it's heating up the inside of your dryer, then it's cooling down the outside air. That causes condensation, which is why you will have water there.