frosting mainline leak

[tcross]

I have a leak that i can not seem to locate. one of my main lines has frost over it for about 8". if the main line is frosted, does that mean the leak is on the main line itself... there are not any wholes near the frosted area? or could it be on a lateral that enters it close by? the frost and leak sound is by 2 saddles but they do not appear to be leaking. the laterals don't have any wholes in them as far as i can tell. i can usually find leaks fairly quickly, but this one has me perplexed! anybody deal with an issue similar to this?

[DrTimPerkins]

It’s probably in the saddle. That is a frequent cause of microleaks and intermittent freezing of mainlines. Those can be difficult to locate and correct. Tighten the saddle clamps and wire tie on each side. If that doesn’t help, replace the gasket or the entire saddle.

[tcross]

thanks dr tim! the problem ended up being a tap in dead wood that was about 6' from the line. the tap never made any noise at all. took me a while, but i found it.

[jrgagne99]

I think that a vacuum leak from a tap in dead wood is among the hardest to find, especially at the top of the lateral line. Glad you found it.

[blissville maples]

If you suspect a dead or hollow tree kink the drop line from the tree for a second then release it and listen for a burst of air similar to how a valve would work on a main line

Especially if there's no sap coming from the spout