Any suggestions?

A weeping joint where the boiler connects to the hot water tank.

The problem isn't fixed there's still certain amount of seepage at the base of the cylinder.

Just a few drops occasionally oozing from the ceiling, but the wall is still sopping wet

sudanglo:Any suggestions?

Here are mine. Certainly not the only possibilities ...

A weeping joint where the boiler connects to the hot water tank.
Gutanta artiko kie la forno konektiĝas al la varmakvujo.

The problem isn't fixed, there's still a certain amount of seepage at the base of the cylinder.
La problemo ne estas riparita, ankoraŭ estas iom da tralikiĝado ĉe la bazo de la cilindro.

Just a few drops occasionally oozing from the ceiling, but the wall is still sopping wet.
Nur kelkaj gutoj foje eksudas el la plafono, sed la muro ankoraŭ estas tramalsekigita.

Eksudi is certainly a useful word here, if it can be generalized from the biological domain.

Elŝvitiĝi looks a good candidate too.

Guteti kaj liketi seem to me to be higher rates of flow. Larmi is too indefinite, but perhaps worth consderation

Trempi seem to imply a deliberate act. Saturita might be OK for sopping wet.

Of course a boiler in a domestic heating system doesn't actually boil the water. So boligilo is technically wrong. Hejtigilo could be an immersion heater or even an electric fire. I think I prefer kaldrono to forno for boiler.

Who has a copy of the new Duden in Esperanto?