Low Inlet Pressure to Hayward 400K natural gas heater

Ok, that seems better.

Maybe some bleed through while it's off.

I don't know if that could be an issue long term as far as possibly damaging the heater's gas valve.

Maybe ask the installer about the initial high reading.

stephenson said:

If the regulator says it is set to 8”, how could it provide 9.62”? I watched the tech unseal the box.

Click to expand...

Every specification has an allowable tolerance.

Between the tolerance of the regulator and the gas pressure manometer, it will be slightly more or less than the specifications.

The service person might have adjusted the pressure, but that should not have been necessary.

Also, it was pointed out that the regulator is not the best quality.

stephenson said:

I fully understand the engineering required and concept of tolerances, both manufacturing and operations - but this equates to around 20% ...

Click to expand...

Contact the manufacturer and see what they say.

I’m sure the gas regulator is good enough (overpriced and marked up but good enough). You’ll get a few good years of life out of it and then you can always replace it with something better later. Don’t let the pursuit of “the perfect” be the enemy of the “the good”. Just make sure the regulator model you have provides enough gas flow for the appliance so that it’s not limiting your flow rate. We had a gas furnace that struggled for a while when we first moved into our home. I had several different “technicians” come out and they all shrugged their shoulders and gave half-cocked excuses for why it was normal and why I was being too picky. They also spent most of the service visit just trying to sell me a new furnace instead of trying to figure out what was wrong with the one I had. After three different companies came out, I decided to take matters into my own hands and within about an hour of poking around the equipment and reading online service manuals I discovered the regulator on the gas pipe was too small for the unit. Whoever did the original equipment installation put a regulator on with too low of a flow rate requirement (our homes in my neighborhood are “housing craze homes” built in 2005/2006 … so they were all built like total crud by “contractors” that were more interesting in collecting their pay than doing a job right …. Never buy a home built in 2005/2006 time frame). After replacing it with a properly sized regulator, the furnace worked much better and the heater didn’t need to struggle to keep the house warm.

Long story short … you’re fine. Go enjoy your pool.