Thread: Discolored Pex

Has anyone seen this before? The Pex was only discolored (blueish) in this area. It's the cold running to the water heater and partially out to the house. The Pex further down the line and back towards the main water line were not discolored. It's Uponor AquaPEX tubing. It's a new construction home, so the plumbing is months old.

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Originally Posted by Jon Errickson

Has anyone seen this before? The Pex was only discolored (blueish) in this area. It's the cold running to the water heater and partially out to the house. The Pex further down the line and back towards the main water line were not discolored. It's Uponor AquaPEX tubing. It's a new construction home, so the plumbing is months old.

Yes, I have seen this on only two houses, I think both were on well water and at least 10 years old. I don't recall the brand of the pipe.

Probably certain minerals in the water, not a big deal as far as I know but you should recommend water testing.

Thanks for the response Bruce. In those houses was it blueish throughout or just in spots? This house is on city water. The pex nearest the main shutoff was not discolored at all. Just near the water heater. I know in the installation instruction it states not to install within 6" of and gas appliance venting -- but this water heater is power vented, so it's not as hot and shouldn't be an issue then, right?

Does the water supply come in from the left? I would question the black fittings in the line. If it comes in from the left, the blue doesn't start until it reaches the first fitting. Just a thought.

Originally Posted by Jon Errickson

Thanks for the response Bruce. In those houses was it blueish throughout or just in spots? This house is on city water. The pex nearest the main shutoff was not discolored at all. Just near the water heater. I know in the installation instruction it states not to install within 6" of and gas appliance venting -- but this water heater is power vented, so it's not as hot and shouldn't be an issue then, right?

I remember one was bluish at the hot water output piping, most of the piping in the house was not visible.

Heat from exhaust vents will not cause this, the spacing is just CYA by the pipe manuf.

A plumber told one of my clients they had some PB pipe but I had already explained in the report that it was PEX that looked the same color as PB due to water or some other issues.

Jon Erricson,

I think you may have a case of blue colored AQUAPEX on the cold side and clearer or "natural" (not white or color tinted) un colored Wirsbo PEXa on the hot water outlet side of the fuel-fired storage tank type water heater.

I was surprised to learn Upanor/Wirsbo produced PEXa in clear/natural (somewhat milky clear) for potable water during a thread string last December, IIRC.

I believe you are mistaken regarding the clearances for AQUAPEX at the inlet, outlet ports and proximity to the power fan and exhaust vent for this fuel-fired storage-type water heater. I'd recommend checking that out with the AHJ in Edina. According to the specifications page on the manufacturer's web site (for the pex named),

Certification of flame spread/smoke development rating of 25/50 in accordance with ASTM E84 PROVIDED the installation meets one of the following requirements:

a. Tubing spacing is a minimum of 18 inches apart for the following sizes: 3/8 inch, 1/2 inch 5/8 inch and 3/4 inch.

b. Tubing is wrapped with 1/2" fiberglass insulation with a flame spread of not more than 20 and a smoke-developed rating of not more than 30 and a nominal density of 4.0 to 4.5 pcf. Tubing can run with three tubes separated by zero inches and then 18 inches between the next group of three tubes for the following sizes: 3/8 inch, 1/2 inch, 5/8 inch,3/4 inch, 1 inch 1-1/4 inch, 1-1/2 inch and 2-inch.

Since it isn't wrapped and is obviously less than 1-inch.... The "zone" above the jacket of the WH has to be respected according to the manufacturer's listed instructions (WH) and local codes. I don't recall at the moment (and am not of a mind to check) if MN plumbing codes are UPC based. UPC used to require all plastic plumbing be isolated 18" in length and 12" min. in distance (forget if it was a 6" horizontal and 12" vertical or how it was worded) from inlet and outlet ports of such WHs IIRC, I haven't verified my recollection, esp. since I haven't verified the plumbing code basis for (Edina?) MN today (and my memory isn't what it used to be on such details).

On another note for this topic string, I do recall very recently mentioning to someone in MN (remember the "dork tag" discussion?) that it was a good idea to RENAME your photos before you uploaded them here (if they contain identifying property addresses from the inspection, and/or client's name), for privacy reasons, etc.

I think it is fairly obvious the inlet is on the right side as photographed (with valve) and the outlet is on the left side as photographed to the clearer, natural colored PEX.

The proximity to the structural metal plate (sharp) indicates to me that the hot water riser SHOULD BE SLEEVED at that location to protect it from damage.

If there are open light sources (which generate direct or indirect UV) to the area, the Pex likely should be insulated/protected from UV exposure.

I would note concern at the path and non-support of the copper tube being used (I assume) for the gas supply plumbing., proximity and clearances of other materials pictured, and unseen less-than-full-story riser support for the pex at the ceiling side of floor junction. I see no supports for the apparently greater than 32" lengths (horizontal/vertical) of PEX tube, nor near fittings.

I am not familiar with specifications for the PEX mentioned, although I admit I was under the impression the proprietary ones for AQUAPEX were brass ringed for potable and not SSC. Was not aware that SSC rings were allowed by the manufacturer, but I do not know if they are allowed to be specified in the manufacturer's installation instructions/handbook for residential potable water systems.

Jon,

Looks like those black fittings are plastic, we have black plastic ones on many new homes around here.

HG: you can see where the blue tint fades away at the top left, those pipes are all the same milky clear type.

HG -- Thanks for the response. I thought that I had changed the name of that photo, but my computer did otherwise. It has been switched now and will never happen again.

The PEX was definitely the 'milky' type throughout, it did not switch to a different color PEX. I went back to the house today and a lot of the discoloration has disappeared (sorry no follow-up, poorly labeled photo). I contacted Uponor and they hadn't seen something like i was describing before. They felt it was likely discoloration due to mineral deposits. I ran a lot of water while i was at the house yesterday. The home has been empty for a few months. Today, a lot of that tubing was back to the 'milky' color. Strange!

What do you mean that the tubing needs to be isolated? ("...all plastic plumbing be isolated 18" in length and 12" min. in distance from inlet and outlet ports of such WHs...") Do you mean there should be insulation over the tubing coming out of the water heater for a certain distance?

In the AquaPEX installation manual it stated it needed to have 6" clearance from all gas appliance venting. But i wasn't sure if that would include a power vented water heater (I think i'll call Uponor back and ask).

That copper tubing (gas to the water heater) was clamped onto the water heater in two spots and at the floor joist above. The pex was supported with plastic clamps once it got into that floor joist area, although I see where that joint needs more support.

I found the instructions manual, and it appears SSC connections can be used (page 31):

http://www.uponorpro.com/~/media/Ext...spx?sc_lang=en

This is a room in the back of the basement with no outside windows, so no worries regarding UV light.

The pex on the cold side of the tank is darker than on the hot side leading me to believe there may be sediment on the bottom of the tank. The cold side having the dip tube is more apt to discolor from small backflows with pressure changes.

I've run into that weird discoloration a couple of times over the years. The last time I found it, it was in a photography dark room in a basement. I just assumed it was from chemicals.

J.E.,

Isolated as in a material other than one which can burn or produce smoke, which is between what can and can not. Further isolated as in a heat sink, metal can put off heat to the air significantly better than PEX and other "plastics", not insulating and futher trapping heat at the top of the jacket. There are numerous other reasons for the prohibition of flamables and the clear or dedicated space at the top zone above the jacket for fuel-fired (yes and some electric) water heaters. See WH's manufacturer's installation and operation instructions and references to your fuel codes, plumbing codes and mechanical codes. You further have an electrical equipment installation (the fan, etc.) in the "zone".

You have again refered to the PEX mfg instructions and stopped there. I advised you that the mfg instructions for the Water Heater, in this case a fuel-fired (gas) storage type water heater. IIRC the clearance exceptions listed in the PEX mfg's specifications/instructions are solely for B-vent zone, I do not recall clearance exceptions for PVC vent.

Code and mfg instructions for the water heater will indicate the ZONE at the top, i.e. the jacket and the area immediately above, which must be respected, i.e. clear of flamable materials. I quoted the PEX mfg's specifications regarding the PEX material's fire and smoke indexes. The "tank" itself is within the jacket. The clearances are of the jacket, etc.

Further the conditons for the soft copper tube GAS line and its support (to the structure/finish) are a problem. Strapping or depending/relying on required support for the gas plumbing to the appliance itself for support is wrong. It futher may violate the clearances required for the gas-fired water heater and its controls. The WH itself although heavy when filled, when unrestrained, can move. Soft coper tube is subject to damage. Many areas it is not allowed for gas supply or appliance connection.

Thanks HG -- I always look forward to your insight. Now I have some water heater manual looking up and further research to do!