I have a problem with a leaking boiler (Vaillant Eco TEC Plus 824), which is about ten years old, but it hasn't had a lot of use (house empty a lot of that time).
There is a slow, steady drip from the right-hand side underneath the casing and an intermittent drip on the left side of the boiler. This stops when the boiler is running. There is no error message.
It doesn't drip straight away when it's off, as it's been off for a couple of days now and only started dripping today. It's done it before and so I called out a plumber but he couldn't find anything as, of course, it wasn't dripping when he called!
Any ideas please?