Had the gas guy over today to hook up our new Hayward 250 electronic. Manual says it need 1 inch pipe. Gas guy ran 1.5 inch pipe, then narrowed it to 1 inch at the heater and then 3/4 inch as in enters the heater. I asked him if that satisfies the manufacture's requirement of 1 inch pipe. He said yes. Does it? Can he use 3/4 inch going into the heater?