Interior condensate pipe

[Kai1981]

Bit of a specific question. I've had a new boiler fitted in a first floor flat kitchen. The safety discharge pipe could be fitted outside but the plumber would need access to it any time there's a problem, plus there's a chance of freezing in winter.

Then other option is an interior condensate pipe, with the pressure release valve connected to a tundish!

But what happens if the boiler fails and there is a leak into the downstairs flat? Is this likely to be covered by insurers or would they usually prefer an exterior safety discharge pipe so the water could run outside? Trying to speak to insurers but posting here too.

I'm not really sure what sort of failure you're thinking about. The condensate pipe produces a slow drippy amount of water (well, condensate) whenever the boiler is running. If the boiler fails the condensate stops being produced. By safety discharge I'm guessing you mean the pressure-relief valve. That can occasionally produce a sudden short burst of steamy hot water if something has gone wrong, not enough to flood downstairs. In any event if they're directed into a tundish I don't see how you're at any more risk than if any other waste pipe in your flat started leaking.

Thanks that's really helpful.

The reason I ask is that the brand new boiler was fitted with a faulty PRV, linked to an external safety discharge pipe. This led to significant water damage on the outside wall and downstairs into the ground floor bedroom wall.

The PRV has been replaced but I guess I'm worried about a similar problem occuring again. That said, it sounds like the issue would be caught fairly quickly if anything similar did happen again.

Ah, ok, we had a drippy PRV years ago which discharged externally and was annoying. The valves themselves can fail like that and let water through, I think if they get a bit of dirt caught in them.

I think the reason your PRV would go into a tundish is so you will see if it's dripping and hopefully call someone out. But the point is that the tundish will catch the drips in the meantime!

The condensate pipe takes condensate away from boiler. This happens regularly and would be a plastic pipe. This should be fitted internally if at all possible, to avoid freezing in cold weather when you need your boiler most. It must be fitted to manufacture's requirements shown in the installation manual. (there are many that aren't) It is no more likely to cause a flood in you home than any other plumbing, if your installer is competent. If installed externally, it is very important it is installed correctly to prevent freezing, especially if access is difficult, or flooding, if fitted to a rain water down pipe (from a gutter etc.). It could also have a condensate pump fitted, to help solve problematic installations, but this is something else to go wrong.

Thank you. I feel reassured about the condensate pipe in that case. Really helpful!