Rusty pinholed Geberit Mappress pipe
Got a leaking automatic air vent? Maybe you had a rubber hose split, you lost a lot of water, then topped up the system without adding more inhibitor? Whatever the reason new water entered the system without inhibitor, this is the end result — rotting pipes, and if it goes on too long — a rotting boiler.
It’s an expensive mistake to make.
The pipe in the picture comes from a system (fitted by one of the many biomass companies that have recently gone bust) where the underground heat main was leaking, and the owners kept topping-up the system with water, roughly once a week, until the pipework sprung a leak. It looked perfectly normal on the outside, then a pinhole started spraying water everywhere. As you can see from the photograph, the inside of the pipe was in bad shape, and there’s no coming back from this — all you can do it cut it out and start again. The bigger problem is that this is a good indication of what the inside of the boiler looks like. It’s likely to be worse, because the intense heat within the boiler amplifies the effect of the rusting agents in the water. This is where the air trapped within the water percolates out, and as we all know, the perfect conditions for growing rust are water + air.
Needs more inhibitor added
What can you do to stop this happening? The main pointers are:
- Quickly repair any leaks
- Regularly test your inhibitor levels
- Consider fitting a water meter on the inlet to your filling loop, or pressurisation unit, so you can monitor how much fresh water is entering the system.