Hi guys - I have recently noticed that when the hot water is switched on I'm getting a little moisture on the underside of my Ariston Contract STI 150 Indirect Protect (one or two drips on the carpet under the unit after the hot water has been on for 20-25mins). When the hot water is not switched on there is no presence of moisture, which makes me believe that maybe this is condensation which has been formed during the heating process? I haven't noticed this before (mind you I haven't been looking) and we've lived in this house for years. After the hot water has been switched off the drops just get evaporated away from the carpet after about 20 minutes. Is this normal?