Vaillant Combi Boiler

Vaillant combi boiler models, guide, comparison, parts, manual, drawings, help

Vaillant boiler dripping water just when heating is switched off

Hello Folks,

Can someone help & identify an issue on my six years old Vaillant boiler. The boiler worked quite well until warrantee ran out. Few days before, after turning off the heating I have observed that boiler is dripping constantly underneath. For getting the desired hot water, I have to top up the boiler’s pressure. The leak would rarely stops for few hours & afterwards again same issue. Should I replace the boiler?

Thanks for your suggestions


Hi Ben,

I think the joint has become a little loose from a cooling cycle and heating. You have to put the leak pan under the dripping range (the leaks would evaporate rapidly), then whenever you shut it down always go through the different joints/connections in a range with wrenches for finding the unfastened joint.

Back to top