Installing PEX on a power vented water heater

**David OKeefe** · 06-08-2015, 05:08 PM

Is this installation acceptable? Is there supposed to be clearance from the PEX to the flue? 6"/12"/18" ? I tried google and looking up installation instructions on both water heaters and PEX but could not find a definite answer. Any help

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**wayne soper** · 06-08-2015, 05:34 PM

NO! power vent! no clearance required

**David OKeefe** · 06-08-2015, 06:03 PM

Originally Posted by wayne soper

NO! power vent! no clearance required

Do you have any reference for that?

From Apollo PEX installation instruction quotes
"Excessive Heat Soldering - Do not solder near Apollo PEX tubing. Water Heaters and Boilers - Use a minimum of 18" of metal tubing to transition between Apollo PEX tubing and the water heater/boiler." It does not distinguish between water heaters.

I also found this from the Uniform Plumbing code.
604.11.2 Water Heater Connections. PEX shall not be installed within the first 18 inches (457 mm) of piping connected to a water heater. Again does not state type of water heater.

**Jerry Peck** · 06-08-2015, 06:56 PM

Originally Posted by David OKeefe

From Apollo PEX installation instruction quotes
"Excessive Heat Soldering - Do not solder near Apollo PEX tubing. Water Heaters and Boilers - Use a minimum of 18" of metal tubing to transition between Apollo PEX tubing and the water heater/boiler." It does not distinguish between water heaters.

Curious why you would use a reference for "Excessive Heat Soldering" when there was no soldering present?

I also found this from the Uniform Plumbing code.
604.11.2 Water Heater Connections. PEX shall not be installed within the first 18 inches (457 mm) of piping connected to a water heater. Again does not state type of water heater.

I may have missed it, but I did not find a similar restriction in the IRC ... why did you choose the Uniform Plumbing Code (most places now use the ICC codes as their base codes - most, but not all)?

The reason for the first 18" is to get the PEX away from the vent heat of a (typically) type B gas vent (the same hot water is going to be going through the PEX directly connected or 10 feet away), and with a power vented water heater ... well, there is no heat build-up to stay clear of.

I could be wrong, but I don't see any reason that would be prohibited.

**Jerry Peck** · 06-08-2015, 07:05 PM

This is an installation manual for their power vent water heaters: http://www.giantinc.com/tech-data/GI-IM015En.pdf

**David OKeefe** · 06-09-2015, 03:47 AM

Originally Posted by Jerry Peck

Curious why you would use a reference for "Excessive Heat Soldering" when there was no soldering present?

I may have missed it, but I did not find a similar restriction in the IRC ... why did you choose the Uniform Plumbing Code (most places now use the ICC codes as their base codes - most, but not all)?

The reason for the first 18" is to get the PEX away from the vent heat of a (typically) type B gas vent (the same hot water is going to be going through the PEX directly connected or 10 feet away), and with a power vented water heater ... well, there is no heat build-up to stay clear of.

I could be wrong, but I don't see any reason that would be prohibited.

Sorry Jerry, copy and pasted more than needed. I was just trying to list all that I found on connecting PEX and water heaters. Looks like it is allowed. I did put in a call to the water heater manufacture, waiting for a reply.

- - - Updated - - -

Originally Posted by Jerry Peck

This is an installation manual for their power vent water heaters: http://www.giantinc.com/tech-data/GI-IM015En.pdf

That manual does not mention type of supply pipe so I assume the type of pipe does not matter.