My vaillant wall mounted combi boiler VCW GB 242 EH (GC-No.4704413) is leaking from the right hand side and this is given me a lot of headache, though the leaking could be described as dripping but requires rectification.I have read peoples suggestions to many problem and i hope there will be a solution to mine as well .

Sam, May 2007

i had the same problem with my boiler aswell i think the problem is the heat exchanger its a black think on the right hand side note you will not be able to get the same part but u will get one that is like it but not exactly same.check on the net for cheap parts

hassan majid, June 2007

Another reason for the drip could be the auto air vent which is located at the top of the boiler, this is designed to release any air from the system but is prone to not sealing properly, this is easily checked by looking over the top right hand side to see if any water is lying on top of the vent.
The cap on top of the vent can be tightened as a temp measure but it is recommended that it is replaced as soon as possible.

Gary Wright, June 2007

Depends which part of the right side is leaking.
The two main items are the diverter valve and micro-switch assembly and directly above that is the cold water expansion vessel(silver ball with small pipe feeding into it).
Two different sets of water. The valve is part of the heating system and could be causing a loss of pressure on the gauge.
The vessel is part of the cold water mains. The pump is also there with several small supply pipes and an auto-air vent.
Vaillant boilers of this type are well constructed appliances and most parts are available. Many of the major components can be repaired with service kits although i wouldn't recommend d.i.y.. there are a couple of safety measure's built into the hydraulic operation which could cause complications if you get it wrong.

T.h.s, May 2007