yeh, they fed me that nonsense also.
THERE WILL BE WATER AND ELECTRICITY, DISCONNECT IT.
I disconnected unit electrical and water supplies, opened up inlet section, applied some silicone grease around the spring loaded seals (must be silicone to avoid damaging rubber seals) put it back together and hey presto!
The spring loaded seals may actually be stuck in as they where on mine so carefully remove them and apply grease.
I also stretched the springs a little as initially they stuck again after a few uses. The seals+springs are in the part that hot&cold feeds enter the unit.
whilst you have it apart it is also worth cleaning the inlet filters!
Have fun, and remember to remove supply before opening as there will be some water.
You'll also need an old towel to dry up water that spills out when taking it apart.
Take note of how it comes apart, better still take photos as you go.
Also, the unit may require to be repowered a couple of times after reassembly to get it to start.
Mine stopped after 3 years, I have now put this down to excessive water temp and adjusted my water thermostat accordingly.
Disclaimer: I accept no responsibility for safety, if unsure get a qualified person to do it!
Paul
November 2012