New answers tagged pipe
Typical of a condensate drain, I'd be surprised if you can't trace the thing back inside and see where it connects (run something stiff-but-flexible up the pipe and listen inside if not otherwise obvious.) Might be from an A/C unit, a condensing furnace or hot water heater, etc. In freezing climates safety overflows are normally prohibited from a placement ...
A pipe like this is often a safety overflow from a central heating boiler. I had the same problem, dripping cold water from a pipe like that in a new built house. It was eventually traced to a wrongly fitted safety valve on the expansion tank beside the gas boiler. I was told by the plumber that, if left, the heating pump would eventually fail. After ...
If you only notice it draining when the air conditioning cooling unit is on, my guess would be it is the condensate drain for the evaporator coil.
The US uses 3/4" straight thread, with 11.5 threads per inch according to Wikipedia
In the U.S. the standard is simply called Garden Hose Thread or GHT,. It's a 3/4" straight thread with a coarse thread pitch and is not compatible with the BSP which is a finer thread pitch.
If this is PVC, 3/4' will slip inside 1" Class 200. The class 200 has a thinner wall, so is larger inside.
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