# Fixing F - ups



## Plumbworker (Oct 23, 2008)

Triangletube boiler installed the previous year with 3 zones two for underfloor staple up and one for in slab. System is direct return (against manufactuers req) needs primary.. 

Well the owner told me "its like a suana" in his downstairs slab level. Upon inspection of the piping i found they were pumping 125 F into the slab ! This temp is safe for staple up but for large thermal mass with slow reaction is no no.. installed a mixing valve now pumping 95 - 100 into slab











Same job the boiler also feeds a indirect with a check on the incoming cold.. no expansion vessel t&p dumping water constantly. So i also sold a mixing valve for the tank and new expansion tank..


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## plbgbiz (Aug 27, 2010)

What does the brand new galvy pipe in the last pic serve?


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## Plumbworker (Oct 23, 2008)

natural gas
"that brand new" is about three years old


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## Widdershins (Feb 5, 2011)

That Laing circulating pump is a ticking time bomb.


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## Plumbworker (Oct 23, 2008)

Widdershins said:


> That Laing circulating pump is a ticking time bomb.


Why...... is the seal going to fail?

then ill be back :laughing: i like the grundfos or Taco circulators


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## Redwood (Sep 8, 2008)

That slab must have been toasty to walk on barefoot... :laughing:

Nice work!


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## futz (Sep 17, 2009)

Plumbworker said:


> Well the owner told me "its like a suana" in his downstairs slab level. Upon inspection of the piping i found they were pumping 125 F into the slab ! This temp is safe for staple up but for large thermal mass with slow reaction is no no.. installed a mixing valve now pumping 95 - 100 into slab


Hmm... Don't they have a thermostat and zone valve for the downstairs? Around here we routinely put that temp or higher into slabs. Often the system designer guys want me to set the mixer at 135F (really! that's what their design program specs). I don't like it that high (too close to the loop limit setting) and usually cut it back to 125F or so. Never had anyone complain of any "saunas". That's what the thermostat is for.  Maybe you have a zone valve failed in the open position or something like that?


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## Plumbworker (Oct 23, 2008)

futz said:


> Hmm... Don't they have a thermostat and zone valve for the downstairs? Around here we routinely put that temp or higher into slabs. Often the system designer guys want me to set the mixer at 135F (really! that's what their design program specs). I don't like it that high (too close to the loop limit setting) and usually cut it back to 125F or so. Never had anyone complain of any "saunas". That's what the thermostat is for.  Maybe you have a zone valve failed in the open position or something like that?


 
ummm i dont think so  as you can see their zoning with pumps i would never pump 125 into a slab the max would be 100 and even thats pretty toasty

by the way the owner is very happy about the new temp downstairs..


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## roving plumber (Apr 25, 2011)

One thing looks typical, mechanical room 4'x6'.....probably have a 10'x20' master closet...


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## Baloo (May 5, 2011)

plbgbiz said:


> What does the brand new galvy pipe in the last pic serve?





Plumbworker said:


> natural gas
> "that brand new" is about three years old


Am I understanding you are using galvanized pipe for natural gas? Here that is a big NO NO. The natural gas attacks the galvanize, and causes it to flack off and plugs gas valves, then eventually leaks.


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## futz (Sep 17, 2009)

Baloo said:


> Am I understanding you are using galvanized pipe for natural gas? Here that is a big NO NO. The natural gas attacks the galvanize, and causes it to flack off and plugs gas valves, then eventually leaks.


Here too. Absolutely NOT allowed. But it seems that in other parts of the world galv is ok for gas use.


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## gtmechanic (Feb 15, 2009)

In NYC no street el allowed on gas line.


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## Marlin (Aug 14, 2008)

We're allowed to use galvanized for gas lines. Any gas line outdoors is required to be galvanized, underground is poly. The gas company uses only galvanized fittings and nipples, they don't carry black in their trucks. I've seen older homes piped entirely in galvanized and have yet to see a gas appliance clogged with galvanized flakes.

I live in Nassau and never heard of the no street ell rule. I've used them and have never been called on it. I know we're not allowed to use bushings which I don't really understand.


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## futz (Sep 17, 2009)

gtmechanic said:


> In NYC no street el allowed on gas line.





Marlin said:


> I live in Nassau and never heard of the no street ell rule. I've used them and have never been called on it. I know we're not allowed to use bushings which I don't really understand.


Street ells are kind of allowed here, but only if you have no other choice, and they'd rather not see them except right at the appliance.

We can use bushings, but only if they drop two sizes (or more), so they've got plenty of metal thickness.


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## ironandfire (Oct 9, 2008)

With galvy flaking, it may have something to do with sulfur content in the gas.


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