My Myson velaire 70/90 stop working and the fault light came on. By pressing the reset button the boiler "fire-up" and appears to be working ok. There is lots of warm water in the base tray. Using a cloth I am able to remove most of the water but there is still positive signs that there is a slow leak, difficult to identify the cause. The pump is ok all visible pipes ok. Any suggestion as to where this water could be coming from?

Ken Kennedy, January 2010

I assume it is a condensing boiler. If so, it could be that the outlet pipe draining the condensate away has frozen. This is a common problem in the current weather. You may be getting a build-up of this water leaking out of the container for it which is located within the boiler casing. On my boiler (which is a Vaillant) the condensate pipe coming out of the boiler is a push fit. With a container held underneath the boiler, simply pull off this pipe. The water which has built up should flow out. This will allow the boiler to re-fire. I've cut the condensate pipe a few inches under the boiler and am collecting the water in a bucket. It comes in short bursts because of a siphonic action out of the container in the boiler, and should be a manageable amount which can be poured away each day. When the thaw comes, I will replace the output pipe aiming to get it better insulated particularly where it goes through the wall and outside. I hope this helps.

BH, January 2010