Help Jandy JXI 260N Frustration!

[swamprat69]

You would think I was on a phone texting with autocorrect

 

[setsailsoon]

I don't think you need to be worried about the combustion blower Rear'y. because if it was not working correctly you would not close the normally open contacts on the air pressure switch and put power to the pressure switch proving terminal (PS) on the fenwal ignition module to start the ignition sequence. If you wanted to check the combustion blower Rear'y, just use a multimeter to check the 8mfd/370v ( + or - 5%) capacitor under the end cap of the motor and make sure that the running amps are under the listed full load amps (FLA) on the motor nameplate.

Swamp,

Thanks, that is definitely a better approach. I'll check it today. Also my digital manometer will be here by Thursday so I can check the diff pr. I previously checked the amperage on L1 and L2 with the fan running and got .41 amps Vs .68 for stamped on the motor so I think the motor and capacitor are likely good. I'll confirm with the test at the capacitor as you suggest.

I also took the vent assembly off the heater to check for obstructions. Nothing changed even with the assembly completely removed. I'm really running out of things to check 'till the digital manometer gets here other than to set up my circuit to prove the ignition module really will properly sense the leakage to ground after turning off power to the igniter and keep the gas valve open.

Can't tell you how much I appreciate the help!

Chris

 

[setsailsoon]

You would think I was on a phone texting with autocorrect

Weird! I just got my laptop back because 3 of the keys started typing on their own sometimes and wouldn't work at all other times. Had to send it in to get the key board replaced.

 

[setsailsoon]

Swamp,

One thing thing I noticed before I replaced the gas valve is that the differential adjustment (under the brass cap screw) didn't seem to make any difference to my problem. In fact, I couldn't discern any change in the flame (visable in the small glass viewing port). I turned it 1.5 turns in both directions. Is this normal? I haven't changed anything on the new gas valve.

Chris

 

[setsailsoon]

Update:

• The digital manometer came and I checked the inlet gas pressure with burner firing. Results were almost exactly the same as my home made manometer -4.7 in H2O and within spec.
• I rigged up my current leak circuit to the black igniter wire. Circuit seemed to be working but no change. Flame still goes out after 7 seconds indicating the control module didn't sense flame.
• Thought there might be a differential between L1 and L2 for some reason that is interfering with ground and micro amp signal. Switched L1 and L2 connection - No Joy. Wired unit for 120v (this uses the neutral bus and I thought this might be beneficial) - No Joy. Unit still turns off flame after 7 sec.
• Checked blower motor capacitor - measured correct but it was cheap so I replaced anyway. - No change in heater operation
• Now wondering if there is a wire that has burnt up that I can't see that is interfering with current detection within the ignition module operation (yeah I know, long shot!).

So far, I've replaced or verified with tests:

• Power distribution board
• Universal control board
• Air pressure switch and all other sensors.
• Ignition control module (replaced twice after first replace from Ebay proved faulty)
• Gas valve (replaced with new)
• Inlet gas pressure
• Burner tube
• Igniter
• Power supply from L1,L2 and switched to 120 vac. No change in heater behavior.
• Built my own "leak to ground" circuit that should emulate a good flame sense. Connected it and no change. Voltage test during ignition at control module test point still measures about 150 mv instead of 2+v. Definitely increases during flame from 8 mv to 150 mv but not enough.
• Removed, cleaned and replaced all ground wires to housing and fire box. Even added an additional ground wire from blower flange.

Next steps:

• Verify the differential gas pressure is -.2 in H2O, adjust if needed
• Check each wire that is plugged into ignition module has continuity to the other end (desperation long shot!)

I'm running very short on options... I've DIY diagnosed and repaired a lot of complicated, modern home appliances and never been unable to fix. This one may be the first failure on my part. Frustrating!

Chris

 

[setsailsoon]

Folks,

After some unplanned travel I finally had time to finish trouble-shooting the heater. I've learned more than I ever wanted about heater controls and flame sense technology. It's what it took to out what my heater problem was! As far as I can find this problem has not been described in publicly available literature. Long story short, I have an interference signal on my ground in the heater circuit. Ground issues are well-documented but all that's described as the fix is to repair "poor" grounds. Nothing I could find describes the problem as being related to any kind of interference signal. All my ground connections had been replaced and I even added the additional direct ground recommended by Fenwal (manufacturer of the ignition control module on many pool heaters). It involves adding a ground wire directly from the burner or flame tube to the ground gang in the control raceway. I found it on the website of the company that owns Fenwal (United Technologies). Pentair sells a kit to do this for their heaters but I couldn't find any documentation as to why it is used. Even with this perfect heater ground, it's still possible to have the flame sensing system fail even if all grounds within the heater are perfect. This is because the flame detection system on all modern heaters works) by producing and detecting a tiny current (couple of millionths of an amp, millionth's not thousandths!). This is so small that it wont even trip a gfci breaker. So it doesn't take much to interfere with it. I'm not sure exactly what the interference is from in my system but I've narrowed to down to either a digital load shedding module on my whole house generator or something in the local wiring. I'll track it down tomorrow. In the meantime, I ran a temporary completely separate circuit to the heater and it is now working flawlessly.

I'll add all the details after I "clean up" my ground.

I hope this helps somebody avoid all the tribulations I had to go through.

Chris

 

[setsailsoon]

Folks,

I would be remiss if I didn't thank all that responded to this post. Thanks for taking your time and sharing your expertise. This was a long road to fix a LOT that went wrong with my heater after a lightning strike that was made much worse with a careless error of mine (dumped a cup of water on the electric controls while energized). But true to form TFP expertise helped me figure out everything that was wrong and I even was able to find a new issue that can prevent heaters from working. I also learned a few new tricks to trouble-shoot specific problems that I'll document in a separate thread.

Again, thanks to all!

Chris

 

[ajw22]

Chris, you have any idea how your ground problem was caused by the water spill? It sounds like the ground problem occurred independently which confused diagnosing all the water spill problems.

 

[setsailsoon]

Chris, you have any idea how your ground problem was caused by the water spill? It sounds like the ground problem occurred independently which confused diagnosing all the water spill problems.

Allen,

Yes, I sure do and you are right on the money with your guess. I was so focused on the water causing the issue I completely neglected to back up and ask myself "what else could be causing this?". Just prior I had replaced the entire sub panel when I converted from Jandy RS to the Pentair Intellicenter. So there could be a simple problem with the wiring such as a neutral and ground reversed or a bad connection somewhere Also, we recently had experienced some problem with our generator. The generator uses two load shedding modules that measure frequency. When it drops a couple hz the system starts to shed loads so the generator won't get above max load. One of my shed loads is all the pool equipment so it's in the sub panel supply. Could I have a failing load shed module?

Armed with my broader view, I decided to start with the easy check and I ran a temporary power supply all the way back to a separate circuit on the main panel. The heater is actually a very low load circuit so I just tapped into a nearby wall receptacle. With this simple change the heater worked perfectly. So I was down to a couple of causes:

• My panel had a leak to ground from the modified wiring when I did the panel replace.
• My recent genset problems were caused by a failing load shed module.
• Something in just the sub-panel circuit for my heater was array.
• Something is wrong with just my heater circuit.

It was simple to run a temporary supply around my existing wiring inside the conduit. If this made the heater work I knew it was in the local to the heater conduit enclosed wiring. I just installed the temporary wiring this morning and found this solve it. Whew! I was really hoping to avoid having to check every connection in the panel. So there's a leak in the insulation, neutral/ground issue, or bad connection. I should be able to trace it down today.

So, in the end I probably purchased a part that wasn't needed to fix the heater but I'm certain all the boards needed replacing since they were visibly burned up. My total cost of repair was about $1100 and probably could have been around $850. But when I do a DIY repair there are benefits. Normally cheaper than a repair tech, I get to buy a new tool, I learn a lot, and I get to crow a lot when I beat it!. For this problem the latter was the best part. It became a "me against the heater" battle and I won! (with a lot of help here of course).

Chris

 

[swamprat69]

One of the problems when electronic HVAC thermostats first came out was feedback from the electronic circuit board in the furnace causing an intermittent bad reading on the flame rectification circuit. The solution ended up being installing an isolation relay to separate the 2 circuit boards when it was in the heating mode.

 

[setsailsoon]

One of the problems when electronic HVAC thermostats first came out was feedback from the electronic circuit board in the furnace causing an intermittent bad reading on the flame rectification circuit. The solution ended up being installing an isolation relay to separate the 2 circuit boards when it was in the heating mode.

Wow, I bet that was a nightmare to detect! I pulled 3 brand new conductors today. Wife and I got pretty good at this when we re-wired a 30 year old sailing sloop. Still had a little cable lube left and it came in handy. I went ahead and switched to solid core. All the existing wiring is stranded and I know it's easier to pull but I much prefer solid core for the breaker box terminations. As expected, the new wire works like a charm.

So now I'm wondering what was wrong with the wire. My best guess is that my water spill with 240 v wired to the power distribution board may have caused the conductors to arc through the insulation. This could have caused a leak to ground that interfered with the flame sense circuit. I'll look at the wires very closely tomorrow to see if I can find any of those tell-tale black dots.

In the meantime the pool is heating on its way up to 92 deg and I'm chilling the gin for a celebratory Martini in the pool tonight!

Chris

 

[setsailsoon]

One of the problems when electronic HVAC thermostats first came out was feedback from the electronic circuit board in the furnace causing an intermittent bad reading on the flame rectification circuit. The solution ended up being installing an isolation relay to separate the 2 circuit boards when it was in the heating mode.

Swamp,

The heater's working great now and we're using it a lot. I did get a differential manometer to set the regulator as you recommended. Had a lot of fun playing with my new toy. The new gas valve was a little off running closer to -.1 in H20. So I adjusted to an average of -.25 in H20. The spec is -.2 +/-.1. I did notice it varies a lot but the meter I have allows you to get the hi lo and average for a period of time. It shows a low of -.35 and a high of -.13. Is the variation normal?

Chris

 

[swamprat69]

In all of the negative pressure gas valves that I have checked and adjusted, I have been able to get a pretty stable reading. Since your combustion fan assembly should be running at a pretty stable speed, I would check the gas pressure at the inlet side of the gas valve while the heater is running to make sure that your inlet gas pressure is stable while running.

 

[setsailsoon]

In all of the negative pressure gas valves that I have checked and adjusted, I have been able to get a pretty stable reading. Since your combustion fan assembly should be running at a pretty stable speed, I would check the gas pressure at the inlet side of the gas valve while the heater is running to make sure that your inlet gas pressure is stable while running.

Thanks for getting back to me. I think it was pretty stable at 4.7 in H2O but I'll double check. If it's swinging then I guess the upstream regulator would be the suspect? Each line that taps off my meter has a separate additional regulator. There are 3 lines, one to the house, generator, pool.

 

[swamprat69]

Normal minimum supply pressure to the gas valve is .25 psi or just under 7" WC for natural gas. Average supply pressure to the gas valve is 7.5"-8.0" WC. Check pressure to gas valve with system both running and not running. If you have 7" WC - 8" WC when it is not running and it drops to 4.7" WC when it is running then look to an upstream problem i.e. pipe sizing/ length of run, restriction in piping or problem with the upstream regulator. If supply pressure is 4.7" WC when it is not running you need to adjust the upstream regulator to 7.5' - 8.0" WC.

 

[swamprat69]

The last part of the last sentence should be 7.5" - 8.0" WC

 

[setsailsoon]

Swamp,

The 4.7 " H2O reading up stream of the heater is with the heater running. Static pressure without the heater running is about 8" H2O. But I do notice the operating pressure swings from 4.6-4.8... seems like this could account for my differential swinging. Maybe I just replace the regulator on the supply line that is downstream of my meter? They're not very expensive so I could just replace with the exact same model.

Chris

 

[swamprat69]

Gas pressure upstream should be able to supply the heater at 7" WC to 8" WC even with the heater running. Since it isn't, it would seem to point to a problem upstream. I would check the three things that I mentioned, but also realize that the problem could also be upstream of the individual regulator for the heater. Depending on the age and materials of the gas supply to your house, you could have a corroded or restricted pipe further upstream in your gas supply system. If access points are available, you could start checking pressure backwards from the upstream side of the heater regulator.

 

[setsailsoon]

Swamp,

Thanks so much. Looks like I have some work to do. The house is a 2013 construction but the regulator looks in pretty bad shape. Vent cap is broken off so it undoubtedly got water in it. I'll check the things you mentioned tomorrow.

Many thanks!

Chris

 

[setsailsoon]

Folks,

This may be my final note on this thread. I want to follow up in case anybody reads this in the future. Previous to replacing my feed supply wires that seemed to be leaking a signal to ground I measured no more that 150 mv on the ignition control rectification current test pins. As James pointed out a long time ago on this topic it's really best to measure true rms current. Voltage is a way to do this that you can infer current from. Probably not as good but I didn't want to buy a fairly expensive meter. My VOM can measure the voltage fairly accurately. With my leaky supply wires replaced the test pin voltage is reading 6.3 volts which equates to about 6 micro amps, well above the minimum 1.3 or so. Maybe well above typical 2-3 because of my enhanced ground system.

Everything is now buttoned up and running fine. It seems I do have a little variability in supply gas pressure but I'm tracking that down separately with some great advice from @swamprat69 . Hopefully it's just a faulty regulator but the supply is still adequate to run the heater.

Thanks again all for the help.

Chris