Contractor Talk - Professional Construction and Remodeling Forum banner
1 - 15 of 15 Posts

·
Registered
Joined
·
559 Posts
Discussion Starter · #1 ·
Hey guys I have a customer that I do some maintenance work for that keeps getting pin holes in his hot water line.
Here are the facts: the house is about 8 years old, the line is 1/2 copper and is the recirculating line for the hot water. They are on a private deep well. I have fixed maybe 6 holes in the last year and half. Anybody have an idea?
 

·
Registered
Joined
·
13,412 Posts
Check to see if they used a cast iron recirc pump, they're supposed to be bronze or plastic for potable water but I have seen iron.

You may need to change the pump or install dielectric fitting(s).

Tom
 

·
Registered
Joined
·
16,403 Posts
I have seen recirculating lines wear out far faster than they would if they were standard lines. If they used the type M instead of L or K on that line then it could wear through and pin hole in no time at all. Of course the water being more acidic can make this issue progress even further especially when heat is involved.
 

·
Registered
Joined
·
818 Posts
Stray current corrosion? Is it grounded properly?
 

·
Registered
Joined
·
221 Posts
I've had the same problem. I'm on a well, 80 gallon tank, all CPVC pipe except the connection between the water heater and the pipe in the wall. When I built the house I installed two flexible copper pipes, but got pinholes about the fifth year. I changed them out to braided lines and have been fine for the last 7 or 8 years.
 

·
manipulator of wood
Joined
·
835 Posts
check the ph level of the water. I have a well and had to install an acid neutralizer. add calcite to the water every few months. pinholing stopped. it was really starting to get annoying after a while.
 

·
Registered
Joined
·
7 Posts
Acidic water...I just repaired a pinhole yesterday in a building's hot water line.....and this was the 5th one in 3 years.....they'll keep popping up too. Acidic water combined with type M copper and a recirc line that constantly has water flowing through it is a recipe for pinholes.
 

·
Registered
Joined
·
819 Posts
from my experience its most likely the recirc pump...have you noticed the pin holes are about 3" or so from 90's?? the 90's twist the water and wear out fittings when the pump is too strong....ive seen this many times and its always been the same...ive always taken out the pump completely and let the recirc go by gravity....its been a 100% success.....ive never run into a situation where a pump was needed yet...gravity always works for me
 

·
Registered
Joined
·
55 Posts
I would guess you piping not being reamed is more likely the issue, rather than the ph level within the water, if the water quality was the issue pin holes would be everywhere not so much near the fitting,, just my opinion ...
 

·
Registered
Joined
·
55 Posts
Serviceplumber said:
I would guess you piping not being reamed is more likely the issue, rather than the ph level within the water, if the water quality was the issue pin holes would be everywhere not so much near the fitting,, just my opinion ...
Sorry I just re read the thread..I'm gonna quit drinking for the nite
 
1 - 15 of 15 Posts
Top