Case study to determine root cause of Pentair mastertemp 400 not igniting

It's odd that the pipe near the meter going into the ground is 1-1/2" or 1-1/4" but it changes to 3/4" underground.

It doesn't make sense to switch to 3/4" until the pipe gets to the heater.

3/4" is too small for any pool heater.

It raises the question about the quality of the line from the meter to the yellow poly.

It would probably be best to replace the entire line if possible.

Hopefully, it will work just replacing the line from the yellow poly to the heater.
 
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I would hope that is a good sign that the riser to the meter went in with the poly and is larger to accomodate the poly. It is odd that they wouldn't replace the rest of the line, but some people are really cheap and just patch stuff together. I bet originally it was all 3/4" and either they never had a heater working well, or sometime when the pool was originally built (or planned), it was like a 150k BTU heater. A lot of people undersized things because, again, cheap.
 
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It's odd that the pipe near the meter going into the ground is 1-1/2" or 1-1/4" but it changes to 3/4" underground.

It doesn't make sense to switch to 3/4" until the pipe gets to the heater.

3/4" is too small for any pool heater.

It raises the question about the quality of the line from the meter to the yellow poly.

It would probably be best to replace the entire line if possible.

Hopefully, it will work just replacing the line from the yellow poly to the heater.
Ya, this is my only path without breaking concrete, so even though its a gamble, I think its worth a shot. an alternative would be an above ground (steel?) line running alongside my property line, not sure of all the legalize behind that...
 
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I would hope that is a good sign that the riser to the meter went in with the poly and is larger to accomodate the poly. It is odd that they wouldn't replace the rest of the line, but some people are really cheap and just patch stuff together. I bet originally it was all 3/4" and either they never had a heater working well, or sometime when the pool was originally built (or planned), it was like a 150k BTU heater. A lot of people undersized things because, again, cheap.
Ya, I have no idea we moved in last June...
Unless they re-poured new concrete after, I don't see signs of any demolition.
Of course there's also a chance the tracer wire I was tracking was an old pipe :( and they may have taken a different route on a replacement job
 
Since the line comes out of the ground by the heater at 3/4", I suspect that they didn't want to deal with the concrete and probably just connected somewhere in the red circle to the existing 3/4" line, but they could have easily run all the way to the heater outside the concrete.

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Update:
been a bit busier at work, but progress. I have a good view of the pipe and joint and before I cut to check gasflow, I want to run my findings by you guys.
Yellow pipe from meter is faded relative to the original find after the elbow joint. perhaps a repair job?
Is this elbow joint acceptable, it looks sealed and not leaking. also, I am proposing where to make my cut to A. check anecdotal flow at meter, B. splice in new 1.5" line.
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I could be dead wrong but I do not believe that the sch40 PVC elbow is an allowable installation for a gas line. When my line was placed we tee’d off the main 2” line with a 1-1/4” line for the BBQ & fire pit and had to use a very special clamp on style connector to make the tee. Cutting the main 2” line was not permissible under code.

Again, I could be wrong but what you have there is a leak waiting to happen.
 
Ya, I was not expecting an irrigation looking elbow, I guess I can replace it with a proper elbow fitting IF there is good flow to this point.
I Don't want to repair a line that will never work! so I'm at a crossroads; can I tap into this line, starting with a new elbow fitting and run 30 feet to heater, or I scrap this old line and plan on a new complete ~125 foot run (not ideal of course)
 

Types of fittings and connection systems for PE gas pipe​

All types of fittings used for PE pipe fall into (2) distinct categories - mechanical fittings and fusion fittings.
Mechanical fittings are most common for low-volume installations, including residential and light commercial projects with pipe size not exceeding 2". They include:
  • Compression-style PE pipe fittings - work in a manner similar to most compression type fittings in the plumbing & heating industry. They utilize a compression ring, ferrule and nut to create a leak-proof connection. PE gas pipe fittings we sell are compression style. Compression PE gas pipe fittings are reusable and economically-priced, making them a popular choice.
  • Con-Stab ID Seal® fittings are push-to-connect style fittings, which work in a manner similar to SharkBite®, where pipe is inserted in the fitting and is held inside by a retainer ring, while sealing O-rings prevent gas leakage. Con-stab gas fittings are the easiest to install, but also cost significantly more that the compression counterpart, are non-reusable and require chamfering.
Fusion connections are less common in the residential market and are primarily intended for larger pipe sizes, such as 3" IPS and above. They utilize special equipment & tools and require special training. There’s a variety of PE fusion connection techniques, including:
  • Butt fusion (incl. saddle fusion) - applies heat to the butt of the pipe and the fitting assembly, fusing them together.
  • Socket fusion - heat is applied both to the fitting and the pipe surface (separately), until both reach desired temperature and start melting. Afterwards, the pipe is inserted into the fitting and both are held together until cooled off.
  • Electrofusion (EF) – utilizes electricity to fuse the fitting (made of conductive material) and the pipe together.

yellow-gas-mdpe-butt-fusion-90-elbow-pe2406-pe2708__47256.1340894216.1280.1280.png
 

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That looks like PVC pipe and a PVC elbow.

Can you show all writing on each pipe?

I would recommend that you replace the entire line.

You can trench through concrete by using a concrete saw so that you don't need to bust up a bunch of concrete.
 
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The elbow looks like PVC or the pipe/line it-self?
the 'brighter' yellow line does not have visible print/markings
I really want to avoid a new line but realize it may be unavoidable; as It takes this project from 30 feet no concrete to ~125 feet with concrete..
 
Oh wow, prob used in the 1980’s I’d guess it’s the original from 1987; would this be suboptimal or a hard no go and may have degraded causing my flow issues?
 
The 3/4" galvanized metal pipe is a major source of restriction.

PVC might have been legal when it was installed, but it is probably not legal today.

You might be able to legally repair it, but I would recommend a full replacement.

_____________________________________________________________________________________________

1208.6.5 Plastic Pipe, Tubing, and Fittings

Polyethylene plastic pipe, tubing, and fittings used to supply fuel gas shall conform to ASTM D2513. Pipe to be used shall be marked "gas" and "ASTM D2513."

Polyvinyl chloride (PVC) and chlorinated polyvinyl chloride (CPVC) plastic pipe, tubing, and fittings shall not be used to supply fuel gas. [NFPA 54.5.6.4.1.1 — 5.6.4.1.3]

_____________________________________________________________________________________________

1208.6.5 Plastic Pipe, Tubing, and Fittings.

Plastic pipe, tubing, and fittings shall be used outside underground only and shall conform with ASTM D 2513, Standard Specification for Thermoplastic Gas Pressure Pipe, Tubing, and Fittings. Pipe to be used shall be marked "gas" and "ASTM D 2513." [NFPA54: 5.6.4.1]

_____________________________________________________________________________________________

ASTM F2817-10

Standard Specification For Poly (Vinyl Chloride) (PVC) Gas Pressure Pipe And Fittings For Maintenance Or Repair

1.1 This specification covers requirements for PVC pipe and tubing for use only to maintain or repair existing PVC gas piping. This specification covers requirements for fittings for use to maintain or repair existing PVC gas piping.

_____________________________________________________________________________________________

 
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Update:
been a bit busier at work, but progress. I have a good view of the pipe and joint and before I cut to check gasflow, I want to run my findings by you guys.
Yellow pipe from meter is faded relative to the original find after the elbow joint. perhaps a repair job?
Is this elbow joint acceptable, it looks sealed and not leaking. also, I am proposing where to make my cut to A. check anecdotal flow at meter, B. splice in new 1.5" line.
View attachment 418539

View attachment 418533View attachment 418534
Whoa. That looks like all schedule 40 PVC (even the yellow pipe). I wasn't aware anyone ever did PVC gas piping.
PE is tubing, not rigid pipe from everything I've ever witnessed. And everything I've ever seen uses compression fittings, not glued on.

That is weird.

I don't think I'd trust it. It's certainly not industry standard by any means here in Texas. I don't know about local codes where you are.
 
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I would agree with the above. While not at all financially optimal, a complete replacement with proper PE gas tubing, risers and new galvanized above ground pipe is the only reliable fix. Saw cutting concrete is not that expensive and a good gas plumber should be able to do that kind of work reliably.

Or … just get rid of the gas heater and invest the money in a solar heating installation.
 
So doing a little reading, I found several forums claiming that in some places Sch. 40 PVC, molded in yellow to designate gas, was legal for a short time in the 70s. But probably illegal by the 80s. Even then though, you would not use a standard irrigation elbow. It had a steel elbow manufactured with PVC sockets for solvent welding--specific for gas use. Some do use sch. 40 yellow pvc as casing for steel pipes.

I'm reading a few folks have dug up plain white sch. 40 pvc gas lines. Probably illegal, uninspected work done on the cheap in the 70s & 80s.

I wouldn't trust it. Who knows what you've really got? It's more expensive, but cut and pull the concrete and put in a real, modern PE gas line is my advice.
 

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