Any gas line gurus in here ?

CPS Reno

In The Industry
Feb 6, 2019
Reno, NV
For the smallest Hayward H Series Nat Gas heater made (150k BTU) at 180'..........a minimum diameter of 1-1/4" is required. Truly sounds like you have a BBQ line and they can't handle much BTU at all.


TFP Expert
Mar 2, 2011
For 3/4" pipe at 2 psi, you can use a 400,000 btu per hour heater.

This is a two stage system where you would have a regulator near the heater that steps down the pressure to heater inlet pressure.

3/4” pipe at 200 feet will carry 642 cubic feet per hour at 2 psi, which is about 642,000 btu/hr.

If the gas was low pressure, then you would need at least 1.5" pipe for 400,000 btu/hr.
Last edited:


TFP Guide
Jun 4, 2012
western NY
I know the charts don't support this and I did it more as a test than anything... I have a 100,000 BTU hayward running on 50' of 1/2" od line. teed off of a 1/2" black pipe line feeding my grill. I have clocked the heater at the full !00,000 BTU several times. Not sure of my line pressure but, I have never asked for an upgrade.