Hayward H400FDN Ignition Failure PART II

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J

John.Rand

0
Oct 25, 2017
8
mesa, AZ
I'm calling this part II because what brought me hear was a Hayward Ignition Failure thread posted by user Ericky, with the same title, a few years ago. My situation is a bit different.


Heaters about 5 years old, hardly ever used. In the first 2 years I got an "IF". It would light upm ignite but immediate shutoff, try it 2 more times than quit with an IF code. I did a bit of research, but I had never worked on a pool heater before so I assumed it was similar to a water heater and had a bad thremocouple. Well Hayward doesn't use a thermocouple, they use a flame sensor (technically I am uncertain how their flame sensor works from a physics standpoint, it only seems to have one electrical terminal, unless the casing mount is a ground reference.)

Anyway, I replaced the flame sensor and it worked for the infrequent times I used it the following 2 years.

Fast forward to a few months back, I noticed an IF error code again. I'm finally getting around to it.

Same story: Fan turns on, Gas ignites, heats pours out for a few seconds, shuts off. Retries three times. This time I replaced the flame sensor but it hasn't made a difference. Flames still shut off after a few seconds ignition.

I do not have time to figure this out so I need to get some expert advice. Hoping it is a simple issue. I have a voltmeter so I can check voltages, just not certain what I want to look for.

Thanks in advance!
-John
 
Flame sensors use flame rectification. An ac voltage is applied and when a good flame is present, it acts as a rectifier and a conductor. A dc current flows through the flame to the burners. The ignition control module senses the dc microamp current to verify flame.

I would suspect low gas pressure. Verify gas pressure and that the gas supply is sufficient. The main gas meter needs to be sized correctly as well as the gas supply line.

Check the burner orifices for blockage.
 
Seeing this is a 5 year old unit, I would have to suspect that the gas supply is fine. Unless you have added something new to the line that is sucking your pressure down.

Sounds like a bad control board. FDXLICB1930. If it were me I would swap the board and see what happens.

Hayward also says if your unit is the older one with the 3" flame sensor, try replacing it with the 5" one.
 
The main reason that I was thinking pressure is that the problem was present right from the beginning and intermittent thereafter.

Maybe I misunderstood.

Early failure might indicate a borderline gas supply.

Even if you don't test the pressure, at least make sure that the line is sized according to the installation instructions.
 
JamesW said:
The main reason that I was thinking pressure is that the problem was present right from the beginning and intermittent thereafter.
Click to expand...

Yeah he said after he replaced the sensor the first time it worked for about 2 years. It could be a pressure issue but since it worked for a 2 years is why I suspected something else. I've been fooled before so who knows.

Could be spider web(s) as well I guess. I just never seem to run into them on this unit unlike on a unit with open burners like the older ID2 units.
 
Hi Guys,
Just an updated for everyone. After getting James initial response (Thank you by the way James), I decided to investigate the burners for blockage. it was clean as a whistle. So that wasn't it.

NOW:
So one thing I didn't mention, last year we moved the heater to a new property to install in a different pool. As I hadn't used the heater in several months, and as soon as we re-installed it and started running it, the IF error popped up. I assumed back then it was the flame sensor as years prior, but as I didn't need the heater anytime soon, I didn't get around to fixing it till now.

Your comments caused me to suspect the gas pressure. We have an extra large regulator as this gas line is a 2 inch line that feeds the heater, a natural gas BBQ and a fire pit, so I never thought it would be a problem. However one thing I didn't account for was that in the old property we had extremely high gas pressure right to the property, so in the heater we had to dial down the pressure to get the 2 bars needed. When I measured pressure here, I was getting 1.6 w.c. on the inside of the heater. I dialed it up to 2 w.c. (correction from bars), but the external line pressure at the heater value is still lower than desired. Apparently I may need to get the gas company to dial up my pressure to support the heater. I broke down and contacted a hayward rep yesterday who is going to help figure out what exactly I may need as well as if I need to get the gas company to dial in a better regulator for my needs.

Though now I am wondering if maybe I should try the suggested 5" flame sensor as well, anyone know that part number?
 
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2 bars? What are you using to read the pressure?

You need to read the pressure coming in as well as the pressure on the manifold side of the heater.

I take it the "new" location previously had a gas heater there or did you add the line for it?

If I am not mistaken, the kit IDXLFLS1930 comes with both 3" and 5" sensors.
 
Forgive me ps0303, I meant 1.6 w.c. and 2 w.c.. I'm tired this morning and wasn't paying attention to the units I typed in.
These were measured on the manifold side. My inlet pressure however is low, something like 3-3.5 w.c.

That's why I decided I need to contact the gas company. The gas line is new for the property, It was supposed to have been sized properly for the pool heater, BBQ and firepit by the builder. The lines are all accurate but I need my gas regulator to up the pressure it seems.
 

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So is this reg is between the street, service coming in from gas company, and the meter or after the meter between the meter and heater? And there is nothing else on the 2" line that the heater is on?
 
Street -> Regulator -> Meter -> House and backyard hardscapes

The regulator is between the street and the meter, and no other regulator. From the meter to the Heater is a straight 50 foot plumb of 2" line (that same line feed to BBQ and Firepit further on, but I've never run them all simultaneously, well the BBQ and firepit I do often, but not when firing up the heater). The output of the meter T's off to the backyard and into the house, so the heater does share gas flow with the house appliances (water heater, dryer, stove).
 
I would ask the gas company to see if they can put give you 2PSI service. I bet they have that pressure available coming in from the street. You would then need to add a reg on the line feeding into the house and one on the line feeding the heater. Your reading was with the heater running on the manifold side right? I know it's hard to get a reading if the unit won't stay running long enough.

It could be dialed up at the reg but I always like to see 2PSI+ service coming in from the street to begin with.
 
I have the answer. We played around with the gas pressure with help from the gas company. No fix.

A hayward rep came out and looked at it, suggested we take apart the burners again and ensure everything was cleaned out, if that wasn't it, probably a bad motherboard...

we took everything apart, cleaned it out..no fix.

Bought a new motherboard for $200...fixed. Dammit....


Thank you for all your help though..I now know a lot more about this heater than I ever wanted to.
 

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