Which PEX tubing is best? PEX A or PEX B in your radiant floor heating system?

We get this question a lot. As there are a lot of misconceptions about PEX tubing out there. See our posts on PEX Tubing and  5 Biggest Lies About Pex Tubing for previous posts on the subject.

In this post we are going to answer the question about what PEX tubing for radiant heating is best! <span style="sarcasm">Now some may argue different opinions, facts and experiences. And they would all be wrong. Our comparison will show, without doubt what tubing you need to buy for your next job.</sarcasm>

Some of our observant readers may notice we are using lots of action words like "best" which are good for SEO (search engine optimization) and will increase our page ranking. And they would be correct! However, if you read through this with a bit of tongue-in-cheek exaggeration you will find nuggets of wisdom that my help you on your next tubing purchase.

PEX Flexibility

PEX-A, PEX-B is not a rating system (See our post - 5 Biggest Lies About Pex Tubing). It is a manufacturing process. PEX-A has been historically more flexible than PEX-B. It also have been able to use the F1960 "cold-expansion". MrPEX rates the bend radius on their 1/2 in. PEX-A tubing at 2.5 in. Uponor rates their AquaPEX at 4 in. bend radius in an unsupported bend and 2.5 in. for a supported 1/2 in. PEX-A.

PEX-B is notorious for being less flexible than PEX-A. Watts lists their 1/2 in. RadiantPEX+ at 5 in. Bluefin and Everhot sold exclusively on online resellers (I would be leery of these products) are close to 4 in. bend radius. All are only joined using crimp or compression fittings.

However, there's a new PEX on the market, Super-B

LegendFlex has a bend radius of just over 3 in! And is capable of joining using F1960 "cold-expansion" fittings.  AquaHeat by ComfortPro has the same capabilities. That's why we call these tubing's "Super B". They have the Price and Durability of a PEX-B with the same performance and capabilities as a PEX-A.

Advantage PEX "Super-B"

PEX Manufacturer

We've said it before and it bares repeating; where you get your PEX tubing from matters. You are using this product as a building material. In some cases it is literally set-in-stone. Make sure you get your tubing from a reputable manufacturer and a value added reseller.

"Why?" you say. "All PEX the same." "I'll never use the warranty." "I'm just shopping on price and availability." Yada yada yada. We've heard it all.

1. Standards, Codes and Listings - If you've ever done commercial construction, you know you need to have your paperwork straight to get paid. Reputable manufacturers are going to have readily available and detailed product specification sheet showing the standards, codes and listings applicable to the project. Those documents cost money to produce. There should also be an engineering staff that can answer questions like; "What effect will spray foam or pest control sprays have on the PEX?" You may not have these concerns with your residential installation. But you can ride the coat tails of the commercial industry by choosing a product with a professional set of documents.

2. Warranty - We see tubing warranties at 25 - 30 years. But what does that get you. If the tubing is installed in a concrete slab and it goes bad. Is the manufacturer going to assume the cost of tearing up that slab and replacing the tubing. Some of them do. Watts, Legend, ComfortPro, Uponor (with restrictions) offer warranties that cover the cost of replacement. It's like an insurance policy on your installation. Some will just give you more tubing (I'm looking at you Everhot and Bluefin) What good is that?

3. Country of Manufacture - It's getting harder and harder to find anything made in the USA. Most of the time it will be more expensive if domestically manufactured. However, there is value in the added cost. Watts, Legend, ComfortPro are all made in the US. MrPEX is made in Sweden. Uponor has a mfg plant in MN. If the country of mfg is not stated, ask.

Advantage USA Made

Price

Soooo, how much? "Do you get what you pay for with PEX?" Yes and No.

PEX-A uses the Engel method of manufacturing. It was the original method of making PEX and still makes an excellent product. Both MrPEX and Uponor use this method. PEX-A takes longer to manufacture than PEX-B. So PEX-A will always cost a little bit more.

Although PEX-B is cheaper to make, the newer "Super-B" is cheaper still.

Buy an Asian made PEX-B at your own risk.

Advantage PEX "Super-B"

Conclusion - Which PEX is Best?

Taking into account flexibility and fitting choices, country of mfg and company backing it up, and price. The best tubing for your radiant floor heating system is ComforPro's AquaHeat. AquaHeat is made in North Carolina and has excellent flexibility and fitting options. For the price it is our Top Choice.

LegendFlex is our Runner Up. Having all the same characteristics as AquaHeat, LegendFlex is made in Michigan and has an outstanding engineering staff. If price is not your biggest concern but you need a product and company you can build your reputation on, choose LegendFlex.

P.S.

"Wait what about PERT?" Tell them to hire a good marking firm. No one is asking for PERT.