Hayward H300FDN firing loop then IF code

[wuffers]

I think I've read the majority of the posts here with Hayward and IF code, and after a few days wrestling with this, I'm stuck on the next part.

Pool opened early June, and the heater's been working fine since (had to clear out a LO code by cleaning contacts, but that's not relevant). The heater is now going to IF mode after a few cycles of firing up and dying out, and the timing is random. Sometimes it stays on for up to 15-20 seconds, sometimes it lasts only a few seconds.

So here's what I've done so far to diagnose the IF code, using the Hayward Universal H-Series Troubleshooting Guide:

• First pass: Opened up the heater and cleaned and vacuumed pretty much everywhere. There was a lot of rust build up on the top heat fins of the exchanger. Cycled via front buttons and it seemed to stay on for much longer than before. It was up for 10 minutes before I reinstalled the front panel, and then it stopped. I reopened the panel but then it went into the firing and stopped cycle before ending in IF code. It might have been a coincidence with the front panel.
• Second pass: Cleaned the flame igniter and its cover and saw igniter glow properly when calling for heat. Still does the firing and stopping cycle before settling on IF code.
• Third pass: Took off blower to access flame sensor. Cleaned blower base plate and area around flame sensor plate. Cleaned flame sensor contact and tested resistance and continuity. Installed new flame sensor and reinstalled blower. Still same firing and stopping cycle before ending in IF code. Blower air inlet plate does not look damaged. Silly question - is this supposed to blow air out from the "inlet plate side" (grill with square holes)?
  • This is what it looked like:
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  • Old flame sensor:
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  • New flame sensor:
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• Fourth pass: Took apart gas union (it was stuck something fierce..), removed orifices from detached manifold and cleaned them (none of the orifices were blocked). None of the holes of the manifold seemed to be blocked either. Cycled back to bo code and it's still doing its firing up and stopping cycle before ending up in IF code.
• Fifth pass: Finally got the manometer, and here's where I'm stuck. I have a plastic tube that fits over the manometer port, but I don't know how to connect it to the gas valve. In page 16 of the guide, it shows these brass looking connectors. What the heck are these? My manometer came with just a tube and no other accessories.
  • 
  • These ports look to be opened using an allen key:
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• Anyway, that's where I'm stuck at. What's the part that I need to pick up to connect the manometer tube to this port to test it out? I'm really hoping I don't have to replace the gas valve at this point.
• If I'm getting correct voltage, that means the ICB is working properly, right?
• Some other observations: Flame viewport needs cleaning. I didn't even realize it was one till my last pass at it. There is some slight condensation under the air box, and the flame when lit seems yellow.
• One last thing, are there official replacement hex head screws? These are what I'm pulling out of the system, and I found some #10 1/2" metal hex screws at the hardware store:
  • 

Suggestions, thoughts? I can take pictures if more details are needed.

 

[ajw22]

The Honeywell gas valve is not serviceable. If a gas valve is opened it must be replaced.

The heater looks like it has a lot of corrosion which causes all sorts of problems. How old is the heater?

Maybe @swamprat69 can help.

 

[TinFoilHat]

That unit and the screws you removed looks so corroded that you wouldn't even get new screws with threads to bite in the holes. Are you sure you want to continue putting money into this? The metal looks like it could collapse at any time or in the next pool season. Just my observation.

 

[wuffers]

The Honeywell gas valve is not serviceable. If a gas valve is opened it must be replaced.

The heater looks like it has a lot of corrosion which causes all sorts of problems. How old is the heater?

Maybe @swamprat69 can help.

Sorry, I don’t understand what you mean by servicing it. I’m just trying to test it using a manometer. I think these 1/4” fittings is the one I need for that:



Also, not sure of the age of the heater. This is the second season with this pool, but maybe this serial can help identify?

That unit and the screws you removed looks so corroded that you wouldn't even get new screws with threads to bite in the holes. Are you sure you want to continue putting money into this? The metal looks like it could collapse at any time or in the next pool season. Just my observation.

The new #10 1/2” screws work fine. If it’s a repair that’ll last a few seasons it might be worthwhile. I’m “only” a flame sensor and a manometer in at this point (and a pack of screws).

 

[swamprat69]

I don't know if I would want to go down the rabbit hole on this one. The amount of rust/corrosion and deterioration might have you replacing part after part in order to get to the point where the heater can be operated safely

 

[wuffers]

Here’s an update:

• I was able to test the gas valve using a 1/8” ID (gas valve port side) x 1/4” barb fitting. While I appreciate everyone saying not to go down the rabbit hole, this would have been useful information just so I can rule out the gas valve. It did test 7 in-wc in and 2 in-wc out while on.
• The water that I thought was condensation under the air box turns out to be a leak on the heat exchanger.
• I took apart the heater to remove the heat exchanger and found out ruined burners:
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• 
• I dropped by my local pool store to get some opinions on new heaters, and while I had my mind initially set on the RayPak Avia HD, the pool guy also recommended to upsize to 400k BTU and also to consider the Jandy JXI with VersaFlo, as that comes with a 5-year warranty. We also discussed other options such as a Pentair MasterTemp or Hayward HC-series 400 (to save on labor as a drop-in replacement). He wasn't pushy on any particular brand, and he also gave me contact information of his HVAC pro to get his opinion.
• I had a long discussion with the HVAC pro (who now specializes in doing mostly pool installs), and he asked some questions that nobody else did, which pointed to a leaky heat exchanger:
  • If there was steam coming from the heater (yes!)
  • If the flame sensor white portion (the piece that sticks in) was rusted (yes!)
• From pictures I sent him, he recommended to upgrade to 1" pipe (that's what's coming out of the meter), but it goes to a T and splits off to two 3/4" (one to the backyard BBQ, the other to the heater). Also the meter would certainly need to be upgraded, as I am (now finding out) currently already undersized there.
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• I think I'm about 8-10 feet from the meter, so is 1" pipe enough? From the above picture we're looking at (I think) six 90 degree elbows (not sure if the two T junctions count), so that puts me already at 15 feet, plus the about 12-15 feet of the piping to the heater.
• What do people think about the new RayPak Avia? The HVAC pro said he has seen them on new builds but not enough track record. He said CuPro or NiTek, heat exchangers will still fail with poor pool chemistry. Having a VersaFlo should not need a manual heater bypass, or do I still want one? I'm undecided, although I am still leaning towards a RayPak but the Jandy's warranty is a compelling draw.
• Oh, and I was able to decode the Hayward serial number thanks to the Hayward Serial Numbers and Date Codes article - it's an October 2016 unit. So close to 8 years is not bad, although the steam should have been a dead giveaway. It's been like that since we owned it, so I thought that was normal, lol.

 

[ajw22]

Since you need to replace the meter and upgrade the gas piping let your gas technician specify the new pipe size to the heater.

The Raypak Avia has wireless remote controls the others do not have if that is something that benefits you. The Avia has worked fine for some folks while others have had some installation problems due to the newness of it. If you get it make sure you have someone locally who can provide service and warranty on it.

Jandy Versaflo does not eliminate the need for a manual heater bypass. The Versaflo mechanism is mechanical and it has failed on some heaters. The Versaflo lets some water flow through the heater even when closed and if the heater begins leaking or your water chemistry is questionable you want the manual bypass to stop all water flow through the heater.

Heater Bypass - Further Reading

www.troublefreepool.com

 

[wuffers]

I got the Rheem version of the Avia HD 404A. It’s a temporary installation to get us going, as my tech is coming back to sort out the gas pipe and the manual heater bypass.





It’s working well so far, and I am already getting almost 2F per hour on the existing 3/4” pipe (it’s just the last 3 feet) for my ~24k gallon pool. By looking at pool heating calculators this seems to indicate that I am getting the full 400k BTU?

What kind of report or testing should I expect from him as he completes the install?