I'm replacing my heater. The current one is a 250k BTU input. Bigger is better so I want to upgrade to a 400k BTU. I've determined that the meter can handle the additional BTU requirement. However, I've received conflicting information on the gas line. It's 1" pipe about 50 feet from the meter. It seems that max BTU is about 300k. What would happen if I bought the 400k BTU heater anyhow? Would it work just fine but at a lower capacity? We're going to replace the decking and possibly add a spa within the 5-7 years, and we can upgrade the gas line at that time to optimize the BTU, so eventually the gas line will handle the 400k BTU. I'd rather get the max size on a heater now rather than having to upgrade that too when we redo the decking.