Pentair MasterTemp 400 - leaking from Manifold

pete8314

Member
Jun 28, 2010
6
Texas
It was a bit nippy here in TX the last week, and now the ice has melted, I'm trying to determine the damage. Unfortunately we lost power in the middle of the night, so by the time I got to it, everything was frozen solid. The Flowcell is wrecked for sure (I don't care, it was never great) , but there's a small leak from the manifold. Nothing appears cracked, and I've removed and resealed the supply & exit pipes, but after looking closed, there is a small but stead stream of water coming from this area:

manifold.jpg

So, two questions, is this likely to be repairable (I'm doubting it), and if not, is replacement up to the level of a relatively competent DIYer?
 

JamesW

TFP Expert
Mar 2, 2011
24,001
You can replace the manifold, but the heat exchanger might also be leaking.

Remove one of the bottom manifold bolts to see if water comes out of the bolt hole.

Jump to 17:00 in the first video.


 

pete8314

Member
Jun 28, 2010
6
Texas
Thanks, those are great videos; I didn't need to, but I ended up watching both of them all the way through, I wish I could find a pool guy like that! Our heater is only 2yrs old, so I'm hoping it's just the manifold assembly, but will pop a bolt or two out later to check that.
 
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pete8314

Member
Jun 28, 2010
6
Texas
OK, next question, nowhere has stock of the parts (either the basic kit 474200 or full set 77707-0016), most places are sating 'months' for new stock, I assume they're just drop-shipping from Pentair directly.

Is there a way to repair the manifold? It's a tiny, hair-line crack, but I'm not sure what the thing is actually made of, or how to seal it up. If not, I'll just have to loop it out of the system until the part is available.
 

JamesW

TFP Expert
Mar 2, 2011
24,001
I think that I can see a crack in the threads near the O-ring, but I'm not sure.

In any case, just bypass for now.
 

bashunov456

Member
Feb 23, 2021
6
Houston, TX
OK, next question, nowhere has stock of the parts (either the basic kit 474200 or full set 77707-0016), most places are sating 'months' for new stock, I assume they're just drop-shipping from Pentair directly.

Is there a way to repair the manifold? It's a tiny, hair-line crack, but I'm not sure what the thing is actually made of, or how to seal it up. If not, I'll just have to loop it out of the system until the part is available.

I also live in TX and lost power from the freeze. My Pentair 400 ( 2 years old also) is also leaking from the manifold. Have you tried to repair it or you going to replace it? Also, am I doing any damage running it with the small leak for now?
 

Humpjs

New member
Mar 18, 2021
1
Rockwall, TX
It was a bit nippy here in TX the last week, and now the ice has melted, I'm trying to determine the damage. Unfortunately we lost power in the middle of the night, so by the time I got to it, everything was frozen solid. The Flowcell is wrecked for sure (I don't care, it was never great) , but there's a small leak from the manifold. Nothing appears cracked, and I've removed and resealed the supply & exit pipes, but after looking closed, there is a small but stead stream of water coming from this area:

View attachment 176707

So, two questions, is this likely to be repairable (I'm doubting it), and if not, is replacement up to the level of a relatively competent DIYer?
I live in Dallas and have the exact same leak after the ice storm. Curious if you found out if it was just the manifold or there were more leaks? If it's just the manifold, I can replace that myself but if there are more leaks, I'm probably just going to buy a new heater. I hate to keep buying parts and waiting and buying parts and waiting only to keep finding more leaks.
 

Kjsmith93

New member
Jul 21, 2013
1
I am in Houston and have the same issue. I have taken a Dremel to the cracks, inside and out, where possible to create a channel. I have added jb weld kwik (which happens to be almost the same color) to the manifold and it appears to be holding for now. I did build a bypass while I was mucking with the manifold, so I have that on stand-by. I hope this helps someone else.
 

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bashunov456

Member
Feb 23, 2021
6
Houston, TX
ks, inside and out, where possible to create a channel. I have added jb weld kwik (which happens to be almost the same color) to the manifold and it appears to be holding for now. I did build a bypass while I was mucking with the manifold, so I have that on stand-by. I hope
Did you happen to take any pics? I am in Houston also, about to pull my manifold off this wkend to try to seal up the leak