WorcesterBosch Greenstar 25Si/30Si leaking

[ronin4]

Hello, new here today, hoping someone can help. My boiler was fitted into our old airing cupboard in the summer.
In past week it has started to leak/drip. Placing a bucket below the bottom left hand corner of boiler I can see a small amount of water collects each time the heating comes on. The man who fitted it came out yesterday and replaced the seal (washer?) around the last pipe on the far left bottom corner of boiler.
The water had first appeared yellow, but since new seal fitted yesterday eachtime the heating goes on it fills up with a small amount of clear water. Its a small amount, but enough to saturate most of a piece of kitchen towel in one switch on. Once dried and heating is off there is no leak, until it comes on again.
Any advice would be appreciated, I had read about condensation, but this is the first week Ive ever seen it drip and the first time it was dirty yellow in colour, only today it is clear. The pressure is either at 1.5 or 2 (when heating is coming on). The heating has been on the same cycle since October, though it did snow this week for the first time this year. THe radiator in the same room as boiler is usually at zero/* when fitted I was told this would not be a problem?



Thanks for any help coming
Cheers
R.

 

[ronin4]

Sorry should of said where leak was coming from ! Doh!
The last piping from the bottom left hand corner of the boiler has been the source of the dirty water. The Gas fitter replaced the seal and since then if you put your hand right up the piping until into the boiler then the drip can be felt falling right from the join.
Thanks again