Jandy LXI400N heater maddening issue

[Doug520]

This issue is driving me crazy. The Jandy LXI400N heater was working fine. Now, turning it on for the first time this season, it won't work. The heater motor starts up and runs for a long time. Finally, after quite a while you hear a click inside, which I assume is the heater calling for gas? Nothing happens. It eventually shuts down and gives off an ignition fault code. It never lights off at all.
I called in an "authorized" repairman. He put a gauge on the unit somewhere inside. The gauge shows gas pressure to spec, but when the heater calls for gas the pressure drops to below spec. He says that there is a problem with the gas supply. I called in a plumber who checked the gas supply and he says it's just fine.
I then called in a repairman from another place to look at the heater. He said it needed a new igniter. He put one in. No change at all. He put the same gauge on the unit that the other guy did and got the same result. He says it's a gas supply issue. I then called in yet another separate plumber. He says there is no issue at all with the gas supply. Arrrggghhhh!
I then called in a THIRD different heater repairman. He's not sure what's wrong. He believes it's the internal solenoid controlled gas valve, which he believes has an internal regulator on it that he believes is faulty. He wants to install a new one and see what happens. That's all well and good except the darned valve is $500!! If it doesn't fix it I'm out $500 and still have an inoperative heater.
Do any of you out there have any ideas on what could be happening here?? I'm about to pull out what little hair I have left.

 

[1poolman1]

This issue is driving me crazy. The Jandy LXI400N heater was working fine. Now, turning it on for the first time this season, it won't work. The heater motor starts up and runs for a long time. Finally, after quite a while you hear a click inside, which I assume is the heater calling for gas? Nothing happens. It eventually shuts down and gives off an ignition fault code. It never lights off at all.
I called in an "authorized" repairman. He put a gauge on the unit somewhere inside. The gauge shows gas pressure to spec, but when the heater calls for gas the pressure drops to below spec. He says that there is a problem with the gas supply. I called in a plumber who checked the gas supply and he says it's just fine.
I then called in a repairman from another place to look at the heater. He said it needed a new igniter. He put one in. No change at all. He put the same gauge on the unit that the other guy did and got the same result. He says it's a gas supply issue. I then called in yet another separate plumber. He says there is no issue at all with the gas supply. Arrrggghhhh!
I then called in a THIRD different heater repairman. He's not sure what's wrong. He believes it's the internal solenoid controlled gas valve, which he believes has an internal regulator on it that he believes is faulty. He wants to install a new one and see what happens. That's all well and good except the darned valve is $500!! If it doesn't fix it I'm out $500 and still have an inoperative heater.
Do any of you out there have any ideas on what could be happening here?? I'm about to pull out what little hair I have left.

Not sure how old this installation is, but what happens many times with those symptoms is that water has entered the gas line. You will find many who say that can't happen, but after clearing, or having replaced by my plumber, many gas lines I assure you that it can.

There is very little actual pressure in most natural gas lines. So, any water will just lay at the bottom of a pipe until the gas, at low pressure, starts to move. The water will slowly build up at an elbow that is coming out of the ground and just block the flow since the pressure is not enough to get past the now larger puddle.

Since natural gas is not poisonous, a quick and dirty test is to turn the gas off at the supply, usually at the meter, open the union at the heater, turn the gas back on at the meter. If there is water you will hear a gurgling. This is best done with two people as the odor of the gas will be strong and people may start reporting a leak so the gas needs to not be running longer than needed, usually within about 15 seconds.

You can blow the water out by disconnecting both ends of the line and using a shop-vac that has a pressure outlet, a strong compressor, etc. but it will eventually return and is an indication of a crack somewhere in the line that will need to be repaired/replaced. If you do use that method, do not stand at the outlet, the rust that will get on your cloths will not come off.

 

[TinFoilHat]

Doug,

Thank this man. He is a wealth of knowledge.

 

[ajw22]

The heater motor starts up and runs for a long time.

That is the forced air blower.

Finally, after quite a while you hear a click inside, which I assume is the heater calling for gas?

That is the gas vale opening.

He put the same gauge on the unit that the other guy did and got the same result. He says it's a gas supply issue. I

That should have been a manometer. Do you know the static pressure before the gas valve opened and the dynamic pressure after it opened?

then called in yet another separate plumber. He says there is no issue at all with the gas supply.

Did any of those gas plumbers open and purge the gas line?

I then called in a THIRD different heater repairman. He's not sure what's wrong. He believes it's the internal solenoid controlled gas valve, which he believes has an internal regulator on it that he believes is faulty. He wants to install a new one and see what happens. That's all well and good except the darned valve is $500!! If it doesn't fix it I'm out $500 and still have an inoperative heater.Do any of you out there have any ideas on what could be happening here?? I'm about to pull out what little hair I have left.

Could be a malfunctioning gas valve.

Show us pictures of the heater, the gas line into the heater, your gas meter, and the data plates on the ags meter.

https://www.zodiacpoolsystems.com/-/media/ff259efb70e047609915523bef9caf46.ashx

 

[Doug520]

Thank you all. I'm working on the suggestions given. The gas line has a 26Kwh Kohler generator tapped into it as well, and the generator runs perfectly, no issues at all with that. I never run the generator and heater at the same time, by the way. That's not the issue here. However, I bring it up because I believe if there was a significant gas line issue the generator would have running issues as well. Is there some sort of regulator in the gas valve, or is it simply a valve?

 

[ajw22]

Is there some sort of regulator in the gas valve, or is it simply a valve?

Show us pictures.

There is low-pressure gas service and high-pressure gas service, depending on what you have. High-pressure gas service uses regulators for each device.