Jandy Lx400 Heater Problems - Won't Light

[anonymouscuban]

I have a Jandy LX400 Natural Gas Heater. It's almost 2 years old. I have never been able to get the thing to turn on. The heater lights for a few seconds and then shuts off, it then tries again and the same. It goes through three cycles of this and then gives me an error "AGS". The manually says it's not enough gas pressure.

I had two Jandy service guys come out, both from the same place. Neither seemed knowledgable to me. I actually felt I knew more about troubleshooting the problem than they did.

The first guy told me it was that supply line was too small. When I told him I had a knew 1.25" line put in, which is what the manually specified, he said it's probably clogged with plumbers putty. I asked him if he could measure the WC pressure but he said he didn't have his gauge. He left without fixing the problem since it was a "plumbing issue".

To rule his conclusion out, I bypassed the new line and ran a temp line out of 2" PVC from my gas meter to the heater. Same thing... three cycles, no heat. I then made my own gas manometer to measure the level of water columns at the heater's gas valve and then after, before it enters the manifold. With the 2" PVC, I get more than enough pressure at the gas valve. However, I don't get enough pressure after the valve. This is the same with the 1.25" supply line. I took the valve to see if there was anything clogging and found nothing.

I then called the second guy. He comes out, takes a look around, listens to my troubleshooting and concludes that my Gas Meter is undersized. I say OK, easy enough. So I call the Gas Company, they ask me for the size of the meter. I give them the model and they say it's largest residential meter I can get.

I think it's the gas valve on the heater that's faulty. The Jandy reps say "Oh those things never go bad". I can pick one up for $175 which I probably will do just to rule it out. Maybe I'll get lucky and it will fix the problem. Who knows.

So that's where I am today. This has been a royal pain in my @$$ so it's been really easy to ignore the problem. I want to be able to heat my spa this summer so I have decided to get this issue resolved once and for all, even if it means shelling out another $2000 for a new heater.

Any help you guys can give me would be much appreciated.

[ParagonPool&Supply]

damn too bad you didn't try to fix this when it was still in warranty....anyway I have a good amount of Jandy heater experience and may be able to help...

first, I need to know if the blower has ever kicked on or kicks on before the ignition attempt...

second, for now, I need to know if this is wired 115v or 240v...

[anonymouscuban]

damn too bad you didn't try to fix this when it was still in warranty....anyway I have a good amount of Jandy heater experience and may be able to help...

first, I need to know if the blower has ever kicked on or kicks on before the ignition attempt...

second, for now, I need to know if this is wired 115v or 240v...

You sound like my wife a little there Just kidding...

Yes. The blower does kick on before the ignition attempt. It kicks on, then a few seconds later, I here a click which I believe is the gas valve closing. Then it cycles and does it again, two more times before giving me the AGS error. Then I have to turn it off and back on to reset it and try again.

The heater is wired at 240v.

I should mention that I have a new Jandy Gas Valve on order since this is pretty much the olnly thing I have yet to try and all my troubleshooting is kind of pointing to it being the problem. Worst case, I spent $200 to rule it out as the problem.

BTW, I appreciate the help.

[drip]

Hi, is the heater actually lighting? do you feel heat from the vent area? If it is and then it sounds like your flame sensor is not working or and this is more likely, the gas orifice feeding the burner that the flame sensor is over is plugged, spiders love to build webs in there, you sound mechanically inclined so I won't go into how to clean them. Also you might try adjusting it to get into the flame better.

If it is not lighting and just cycling 3 times then AGS then it sounds like your igniter is bad, to test just pull it out just your gas valve off and try to fire the heater, it should glow red hot.

FYI some of the most frustrating problems with heaters when you can't find a bad part is those clogged orifices. Oh, and gas valves very rarely go bad.

If none of this works and someone else can't give you a solution I have a Jandy LX factory troubleshooting flow chart that I'm sure could help you get it figured out, the best I know how to do is to scan it into my comp and email it to you. Let me know.

[anonymouscuban]

Hi, is the heater actually lighting? do you feel heat from the vent area? If it is and then it sounds like your flame sensor is not working or and this is more likely, the gas orifice feeding the burner that the flame sensor is over is plugged, spiders love to build webs in there, you sound mechanically inclined so I won't go into how to clean them. Also you might try adjusting it to get into the flame better.

If it is not lighting and just cycling 3 times then AGS then it sounds like your igniter is bad, to test just pull it out just your gas valve off and try to fire the heater, it should glow red hot.

FYI some of the most frustrating problems with heaters when you can't find a bad part is those clogged orifices. Oh, and gas valves very rarely go bad.

If none of this works and someone else can't give you a solution I have a Jandy LX factory troubleshooting flow chart that I'm sure could help you get it figured out, the best I know how to do is to scan it into my comp and email it to you. Let me know.

Drip,

Thanks for the reply. I will try the things you suggested but I doubt it's a clog. Keep in mind, I've had this problem since the heater was taken out of the box and installed. Also, I do feel heat coming from the manifold so it is lighting. The problem is the valve shuts off after a couple of seconds; I can actually hear when the valve closes. No matter, I will check everything for debris or spiders/webs, etc. just to rule those things out.

Hey, that would be great if you can send me that troubleshooting guide. Please email it to me at anonymouscuban@yahoo.com.

I will keep you guys posted on what happens after I try the different things you all suggested and also after I replace the valve.

[ParagonPool&Supply]

Ok, we have some good collaboration going on here...if your ignitor is truly lighting and the fan works, than you might be encountering the same kind of crazy problem I once had with a Lite 2 which the LX is based off of....I also thought it was the gas valve like you......it might actually just be the 30 dollar voltage chip...I'm not 100% positive if the LX uses the same type of voltage plug as the Lite 2 but I'll check tomorrow at a pool and get back to you...

[ags]

I have a Jandy LX400 Natural Gas Heater. It's almost 2 years old. I have never been able to get the thing to turn on. The heater lights for a few seconds and then shuts off, it then tries again and the same. It goes through three cycles of this and then gives me an error "AGS". The manually says it's not enough gas pressure.

I had two Jandy service guys come out, both from the same place. Neither seemed knowledgable to me. I actually felt I knew more about troubleshooting the problem than they did.

The first guy told me it was that supply line was too small. When I told him I had a knew 1.25" line put in, which is what the manually specified, he said it's probably clogged with plumbers putty. I asked him if he could measure the WC pressure but he said he didn't have his gauge. He left without fixing the problem since it was a "plumbing issue".

To rule his conclusion out, I bypassed the new line and ran a temp line out of 2" PVC from my gas meter to the heater. Same thing... three cycles, no heat. I then made my own gas manometer to measure the level of water columns at the heater's gas valve and then after, before it enters the manifold. With the 2" PVC, I get more than enough pressure at the gas valve. However, I don't get enough pressure after the valve. This is the same with the 1.25" supply line. I took the valve to see if there was anything clogging and found nothing.

I then called the second guy. He comes out, takes a look around, listens to my troubleshooting and concludes that my Gas Meter is undersized. I say OK, easy enough. So I call the Gas Company, they ask me for the size of the meter. I give them the model and they say it's largest residential meter I can get.

I think it's the gas valve on the heater that's faulty. The Jandy reps say "Oh those things never go bad". I can pick one up for $175 which I probably will do just to rule it out. Maybe I'll get lucky and it will fix the problem. Who knows.

So that's where I am today. This has been a royal pain in my @$$ so it's been really easy to ignore the problem. I want to be able to heat my spa this summer so I have decided to get this issue resolved once and for all, even if it means shelling out another $2000 for a new heater.

Any help you guys can give me would be much appreciated.

[ags]

Sorry for the bad post. I have the same Jandy heater and it is about 2 years old as well. They replaced it out of the shoot because the first one did not work. I have been taken through the same process with them blaming it multiple times on pressure. I had a plumber in large my gas line and the gas company bring out the largest meter. I had it working for several months to my knowledge at least the 3 or 4 times I tried it. Recently I had it running for several hours and it heated but suddenly stopped and now won't ignite. Your Jandy friends are coming out again tues. but am doubtful I will get anything more than a bill and the same old answer. My pool builder stopped returning calls early on in the process so he is of no use. I was told this was a great heater but it appears to stink. I will try these couple of things listed. It sounds like this particular heater has issues.

[roff71]

If the heater is burning for a couple seconds then shuts down and then tries again it sounds to me like the flame sensor is not sensing the flame so it is shutting the gas valve down.

Try taking the flame sensor out and take a piece of emery cloth and sand it down then put it back in and see if it works.

[anonymouscuban]

I'm still awaiting the new gas valve so I haven't done anything with the heater since my original post but I thought I won't update the thread.

I've also ordered a gas manometer just make sure I am adjusting the valve properly since I know this same symptom can happen if the valve is allowing too much or too little gas into the manifold. I think I mentioned that I actually made my own gas manometer but I thought I'd spend the extra 60 bucks for a professional one.

Hopefully I will get the valve this week some time so I can fuss around with the heater this weekend. I will try the flame sensor suggestion as well. I will post an update once I try some of this stuff.

Honestly, I went with Jandy because I've heard really good things about them. All of my equipment is Jandy, from the filter and pump to the salt system and controller. Everything else has worked very well and I feel the heater issue is not an example of the normal experience. Just bad luck for me.

Regardless, I have promised the wife that her spa will be heated this year regardless of if I have to buy another heater.

Keep the information and suggestions coming... something gotta work eventually!

[muss51]

Sounds like you could have any number of problems. Possibilities: Ignition control, thermostat, blower pressure switch. All of these need to be tested.

[anonymouscuban]

Sounds like you could have any number of problems. Possibilities: Ignition control, thermostat, blower pressure switch. All of these need to be tested.

I received the new valve today so now I am waiting for the manometer. Also, I got my hands on a Jandy troubleshooting guide for this heater so I now have some direction on how to tackle this problem. I will keep you guys updated.

[anonymouscuban]

Sounds like you could have any number of problems. Possibilities: Ignition control, thermostat, blower pressure switch. All of these need to be tested.

I received the new valve today so now I am waiting for the manometer. Also, I got my hands on a Jandy troubleshooting guide for this heater so I now have some direction on how to tackle this problem. I will keep you guys updated.

Update... So I received the new valve and the gas manometer. I replaced the old valve with the new gas valve and tested the gas pressure before and after the valve. Pressure before the gas valve inlet is 8.75" WC. Pressure at the gas valve outlet was about 3.5" WC but I adjusted it down to 3.0" WC. Basically, pressure is now what the specs call for... still no dice. So at least I have rulled out gas pressure or the gas valve as the problem. I called another Jandy Service Guy who will be coming out on Thursday afternoon. Hopefully, he will be able to get it working.

I will update you guys on progress and findings.

[anonymouscuban]

So... the Jandy Service guy came out yesterday. It took him all of 20 minutes to find the problem. The Flame Sensor was disconnected.

Pretty anticlimactic if you ask me. Don't get me wrong, I am extremely happy that the heater is working. I am just a bit dissapointed that it took almost 2 years to get it working. Part of that is my fault for procrastinating. But I had 2 supposed Authorized Service guys look at the problem and they were not able to figure it out. If not for the fact that I am pretty handy and know just enough about gas lines and mechanical stuff to get me in trouble, I would have ended up shelling out several thousands of dollars running a larger gas line and redoing part of my stamped concrete decking.

I do have to say that I am pretty impressed with the heater. I fired it up yesterday, for the first time, after the Service Guy left. It took about 30 minutes to warm my spa water from 72 - 98 degrees. I will probably heat my pool next weekend to see how long that takes.

Thanks to everyone that made suggestion and gave input on the problem. Hopefully this thread will help someone else out that finds themselves with the same problem.

[ParagonPool&Supply]

i finally fixed my nightmare lx...brand new from factory and this one obviously got housed in shipping...it needed a new fan..igniton module...and ignitor...glad we were still under warranty...we're finally cooking on that pool thanks to my intuition and not Jandy's tech support...aka...the line that tells you to keep swapping parts until it runs...anyone ever have any lx problems in the future feel free to pm me....

[jstreg]

I just got finished reading all these problems, and it' almost like someone was writing the story about my problem. Same thing on the ignition (lighting up but not staying on), low gas pressure so I got a bigger meter. It worked for almost 2 years somehow after a lot of tweaking, but now it no longer works. The tech blames the gas company, gas company blames the heater, Jandy doesn't have a solution. So, can you tell me how to change or check the referenced flame sensor and send me the link to troubleshooting guide. Also, I'm not sure how I adjust the gas valve at the heater. I pretty handy with all this stuff, I just don't have instructions.

[lakeforklady]

Sounds like you could have any number of problems. Possibilities: Ignition control, thermostat, blower pressure switch. All of these need to be tested.

I received the new valve today so now I am waiting for the manometer. Also, I got my hands on a Jandy troubleshooting guide for this heater so I now have some direction on how to tackle this problem. I will keep you guys updated.

do you still have the troubleshooting guide i have same problem u had thanks in advance

[Coldwaterman]

Wow, there is a lot of troubleshooting horsepower on this site! I too have had two years of similar ignition problems with my LX heater, but I get a different error.

My heater follows the pattern below, sometimes 5 or 6 time in a row before finally lighting.

1) Fan comes on "high" for about a minute

2) Gas valve opens and it ignites for a few seconds with "HEATING" flashing in the display, before the flame blows out.

3) Fan remains on high.

4) Second ignition attempt. FAN still on high. Again, some heat out of the exhaust but in a few seconds, it blows out.

5) Fan still blowing on high.

6) Third ignition attempt. FAN still on high. Again, some heat out of the exhaust but in a few seconds, it blows out.

7) SERVICE message blinks and fan shuts down in about a minute.

So I cycle the heater from SPA to OFF to POOL and back to SPA, and it starts back at 1.

Usually, after 5 to 6 times, it does something different.

The Fan goes to a slow speed before opening the gas valve, and VIOLA! ; the heater ignites and stays lit. After about 10 seconds, the fan goes to HIGH but the burner stays lit, and we can enjoy the hot tub. Unfortunately, after the tub reaches temp, the burner shuts off, and the spa starts to cool off, and somebody has to run over to the heater and shiver while they go through 5 or 6 cycles to light it off again. :-(

I don't know why the fan won't go LOW on most cycles, but I know if it stays HIGH, the burner won't stay lit.

Jandy customer support blamed gas pressure, controller, and the installer. Techs have been out, and they say the controller is OK. They said they made "an adjustment", and for a little while it lit easier, maybe on the second or third try. Now two months later, and we are back where we started.

Any thoughts or hints would be most welcomed at this point.

[Pool Clown]

Coldwater, how old is the heater? I ran into this on a heater that was a couple of years old. What happened was years of insufficient gas volume, the heat exchanger sooted up so bad that it would not vent. The burners rely on the exchanger to vent through but when it gets sooted up the hot gases cannot flow through the exchanger and causes this fault. If you have a small mirror, you can put it on the floor of the heater and try to see the underside of the exchanger. Give the heater a call for heat and perhaps you can see the underside of the exchanger. It will start to glow, Kinda like charcoal in a bar-b-q. If you see this, You will probably need to call a tech to have the exchanger de-sooted.

[Coldwaterman]

Coldwater, how old is the heater? I ran into this on a heater that was a couple of years old. What happened was years of insufficient gas volume, the heat exchanger sooted up so bad that it would not vent. The burners rely on the exchanger to vent through but when it gets sooted up the hot gases cannot flow through the exchanger and causes this fault. If you have a small mirror, you can put it on the floor of the heater and try to see the underside of the exchanger. Give the heater a call for heat and perhaps you can see the underside of the exchanger. It will start to glow, Kinda like charcoal in a bar-b-q. If you see this, You will probably need to call a tech to have the exchanger de-sooted.

Sorry about the duplicate post - but the heater has been doing this since day one. It is only about 18 months old now.

[Coldwaterman]

Hi Pool Clown,

Unfortunately the heater is only about 18 months old. and we've been having this problem ever since it was new.

[morke]

I'm having the same ignition problem. In my case, the heater ignites the first time heat is called for. But after the spa gets to temp the heater goes off and will not re-ignite when further heat is needed. It goes through the 3 attempts then displays the "Ignition Fault" error. Last night I tried for over an hour to try to get it going -- no dice. This morning it lit up fine. I've measured the gas pressures and all is well with that.

[bubbadoom]

I'm having sporadic heater problems with my Jandy. Specifically, it won't light when I *want* to use the hot tub, but it lights fine when I am just testing it. 3 weeks ago, on a Saturday, I first started having the problem. The heater has been working fine for the past 7 years. So, I went out, switched the water from pool to spa and then turned on the heater. Assuming it would work like usual, I went inside for 45 minutes. When I came out to check the water, it hadn't heated so I went to the heater and the temperature hadn't changed but the panel said "Heating" and the air was blowing out of the exhaust - but the exhaust air was cool and I could smell gas. So, the next week I had a pool guy come out who found the gas valve was half closed so he opened it fully and the heater started without a problem. The next Saturday, I went to use it again and even though the gas valve was fully opened, it didn't start. It behaved just like it did the previous Saturday. So, I called the pool guy again who told me to try it and tell him what the error message is on the LED panel. During the week I tried the heater at 3 different times (morning, evening), and each time the heater started without a problem. So this past Saturday I tried to use it again, and of course the heater didn't light. I left it running for 10 minutes (to let it cycle 3 times), and the LED said "Heating", but the exhaust air was cool and I could smell the gas again. I tried 3 times on Saturday night, but again it didn't start and I didn't see any error messaged on the LED. I shut the heater down and opened it but I didn't see anything glowing on the inside (I'm supposed to see something glowing if it started, I presume). On Sunday, after a period of heavy rain, I went outside to try it again just to see if it would fail but it started.

Why would the f****** thing start every time I am testing, but not when I want to use it?!?!?!!! More seriously, what could the problem be?

[Pool Clown]

Sticking, or intermittent voltage to gas valve?

When the air is cool, does it run for more than a min or two(the fan)?

Between 15-30 sec after the fan starts, can you hear the gas valve click open?

[austinmf]

Mine is doing the EXACT same thing... We restart it 20-30 times and it finally catches... once the blower hits high, the heat comes out and you can hear the gas burning and wavering back and forth like rows of jets are going off and coming back on.... after 3-10 seconds, it finally stops the gas and keeps the blower on for a cool down.

We restart and try again... eventually it takes but today has been over 40 trys... and it still will not stay lit for more than 20 seconds.... It has NEVER worked correctly from day one....

And it finally came on....