Drip from Heatrae Sadia Megaflo through Tundish

[asktoby]

I noticed a dripping from a pipe on the side of the house outside, once per second.
Traced it back to the tundish in my boiler cupboard. (between 1 and 6 below).

Another photo:

https://kuula.co/share/7P9V6?fs=1&vr=0&zoom=1&thumbs=1&chromeless=0&logo=0

Looks like I need a plumber to come out and diagnose the fault. Any tips?

 

[asktoby]

Wait, only just noticed this helpful sticker:

https://photos.app.goo.gl/Gk35c37rcFszWq8p6

Have followed instructions and it's still dripping, I'll leave it overnight and see if it stops.

 

[Hot&Cold]

Follow the instructions on the label attached to the mega-flaw.

 

[stem]

I've come across the same thing a couple of times. On both occasions it was the expansion vessel that was faulty. It has a rubber membrane inside that has air on one side, and water on the other. If the membrane gets a split in it and the water displaces the air, when the water is heated and expands it can no longer compress the air pocket and so drips out via the safety valve into the tundish. There are other possibilities though, a faulty pressure regulation valve or expansion valve may also cause dripping.

Unvented systems are not suitable for DIY repairs. If wrongly installed or maintained, they can become impressive rockets. Therefore, the Building Regulations require anyone that works on them to hold a G3 certificate as proof of competence.

It won't help with your problem, but what's going on here? This looks like a decapitated immersion heater sitting atop of a pipe.

 

[MeldrewsMate]

Stem, the Megaflow does not have an external expansion vessel, it has an internal air pocket.

OP, follow the instructions on a large sticker on the side of the Megaflow, or ask Heatrae tech for advice if you can't find it.

 

[Hot&Cold]

asktoby best get it looked at (g3 tech req) it may be save able

There may have been an ad-hock alteration involving fitting of an external expansion vessel and the 1-5 label has not been removed.

who knows