Hayward H400FDN "IF" Code

[soundcheckers]

Hi,

Looking for a Hayward expert to come take a look at my H400fdn. I've been trying to troubleshoot it myself and also had my pool guy take a look, but I think he's not that well versed on this heater. I'm in Northern NJ (Ramsey/Mahwah/Wyckoff) Any recommendations?
Thanks!

 

[ajw22]

Welcome to TFP.

I don't have recommendations on a service person to do a house call but we can help walk you though diagnostics.

For the heater to light it takes air, gas and spark and then to keep the flame going you have to satisfy the electronic flame sensing. Those are the four things to check in s structured fashion.

Universal H-Series Diagnostics Guide provides detailed diagnostics for troubleshooting problems and error codes.

Hayward H-Series Heaters - Further Reading

www.troublefreepool.com

 

[1poolman1]

Hi,

Looking for a Hayward expert to come take a look at my H400fdn. I've been trying to troubleshoot it myself and also had my pool guy take a look, but I think he's not that well versed on this heater. I'm in Northern NJ (Ramsey/Mahwah/Wyckoff) Any recommendations?
Thanks!

Remove the leads from the main gas valve and attach a meter set to AC to them. During a try for ignition you should see 24V on the meter. If it goes away in less than 3 seconds you need to replace the TWO boards on the right side of the cabinet. It could be one or the other but replace the wrong one and the bad one will take out the good one. No way to test for which is the bad one. Gotta' love Hayward for that debacle.

 

[soundcheckers]

Remove the leads from the main gas valve and attach a meter set to AC to them. During a try for ignition you should see 24V on the meter. If it goes away in less than 3 seconds you need to replace the TWO boards on the right side of the cabinet. It could be one or the other but replace the wrong one and the bad one will take out the good one. No way to test for which is the bad one. Gotta' love Hayward for that debacle.

Hi,

Thx for the recommendation! I disconnected the leads from the gas valve (white/black,) and connected a multimeter set on AC, and tried to ignite. Blower starts, clicking... NO reading at all. Stays at 0. I then tested a wall outlet in my house, and boom.. 120V so I can assume the meter works. What does it mean that I get no reading at all? Replace both boards? Thanks again for your reply!

 

[1poolman1]

Hi,

Thx for the recommendation! I disconnected the leads from the gas valve (white/black,) and connected a multimeter set on AC, and tried to ignite. Blower starts, clicking... NO reading at all. Stays at 0. I then tested a wall outlet in my house, and boom.. 120V so I can assume the meter works. What does it mean that I get no reading at all? Replace both boards? Thanks again for your reply!

If there was never a reading while the leads were connected to the wiring, either of the two boards may be bad.

 

[soundcheckers]

If there was never a reading while the leads were connected to the wiring, either of the two boards may be bad.

Ok, update... While I was waiting for parts to arrive, I went out and checked the voltage again. This time I was more thorough. I tested the points on the ICB where the wires to the gas valve are connected, and I measured the other end of the wires after I disconnected them from the gas valve. Both tests revealed the same result which was approx 23 volts but only for a second or two while I the heater was calling to ignite. I'm pretty sure the 23v reading coincided with the clicking. The blower starts, then after that the clicking (and I get the 23ish v reading but for a a few seconds, also the red "heat" light comes on for a second) then it repeats the cycle 3 times, and then I get the IF code. Is this a bad gas valve? I don't have a manometer to test but the heater has been working from the beginning of the season whenever I turned it on until just a few weeks ago. How long do I have to get the 22-28V reading in order for it to fire? Any other suggestions to try?

 

[1poolman1]

Ok, update... While I was waiting for parts to arrive, I went out and checked the voltage again. This time I was more thorough. I tested the points on the ICB where the wires to the gas valve are connected, and I measured the other end of the wires after I disconnected them from the gas valve. Both tests revealed the same result which was approx 23 volts but only for a second or two while I the heater was calling to ignite. I'm pretty sure the 23v reading coincided with the clicking. The blower starts, then after that the clicking (and I get the 23ish v reading but for a a few seconds, also the red "heat" light comes on for a second) then it repeats the cycle 3 times, and then I get the IF code. Is this a bad gas valve? I don't have a manometer to test but the heater has been working from the beginning of the season whenever I turned it on until just a few weeks ago. How long do I have to get the 22-28V reading in order for it to fire? Any other suggestions to try?

The voltage at the main valve has to stay on long enough for it to allow gas to flow. According to Hayward, and every one of those heaters I've worked on, a 3-second or less signal (voltage) at the main valve indicates that the boards need to be replaced.

 

[soundcheckers]

The voltage at the main valve has to stay on long enough for it to allow gas to flow. According to Hayward, and every one of those heaters I've worked on, a 3-second or less signal (voltage) at the main valve indicates that the boards need to be replaced.

Thx 1poolman1! Just waiting for the field wiring panel board to arrive on Thursday and then I'll install them both and pray!

 

[soundcheckers]

Installed both new boards. Nothing changed. No ignition. Checked the igniter again. Glows red/orange. Checked voltage... 23-24 volts when clicking/calling for heat but only for a few seconds.
It's gotta be either the gas valve, or a blockage (spider webs)? How to I check the flame sensor? Could it be that?

 

[ajw22]

Maybe @swamprat69 has ideas.

 

[swamprat69]

This should be the manual for your heater https://images.inyopools.com/cloud/...s-asme-heater-service-installation-manual.pdf . The sequence of operation for heating is listed on page 36. The gas valve is only powered for 4 seconds while attempting to light the heater. Is there an observation port in the combustion chamber to observe the burners? Are the burners lighting off at all? The ignitor and flame sensor seem to be on different burners ( ignitor burner lights and flame travels to burner with flame sensor).

 

[swamprat69]

Note: during the attempt of the heater to light off, you can put your hand on the gas valve and should be able to feel if the solenoid is clicking open.

 

[1poolman1]

Installed both new boards. Nothing changed. No ignition. Checked the igniter again. Glows red/orange. Checked voltage... 23-24 volts when clicking/calling for heat but only for a few seconds.
It's gotta be either the gas valve, or a blockage (spider webs)? How to I check the flame sensor? Could it be that?

Flame sense only works if there is flame so it's not that if the heater never lights.

When the system calls for heat, is there a click from the main valve? I've only heard of a bad valve taking out the board one time, so didn't really consider that.

If the voltage to the valve lasts for more than 3 seconds (per Hayward tech support) and you don't hear the valve make an audible click, the valve may also be bad. Less than 3 seconds its in the board somewhere. Your first tests were less than 3 seconds.
You can always remove the orifice right at the hot-surface ignitor and check for spider nest as well.

The flame-sense rod is connected to the white wire near the ignitor. Two screws hold it in. It can be removed and cleaned with a dollar (5, 10, 20, 50, 100) bill, especially a newer one. They have just the right amount of abrasiveness to clean deposits without removing the coating on the rod. A fine Scotch scrubber works as well. Never sandpaper. Old HVAC trick.

 

[soundcheckers]

Note: during the attempt of the heater to light off, you can put your hand on the gas valve and should be able to feel if the solenoid is clicking open.

This should be the manual for your heater https://images.inyopools.com/cloud/...s-asme-heater-service-installation-manual.pdf . The sequence of operation for heating is listed on page 36. The gas valve is only powered for 4 seconds while attempting to light the heater. Is there an observation port in the combustion chamber to observe the burners? Are the burners lighting off at all? The ignitor and flame sensor seem to be on different burners ( ignitor burner lights and flame travels to burner with flame sensor).

If there is an observation port, I have no clue as to where it'd be. The sequence I'm getting is as follows.
1. I call for heat
2. The blower starts
3. After about 10-15 sec, I hear clicking (I put my hand on the gas valve and definitely felt some sort of clicking/vibration,) as well as the green 'heat" light on the front display lights up but just for a split second and then the cycle starts all over again. After the third attempt, I get the "IF" code.

On a side, when the heater was functioning, I always would smell gas when it ignited. Now when I attempt to ignite it there is no smell at all which makes me suspect that it's the gas valv.e

How do I check if the gas valve is working, or if it's stuck?

 

[soundcheckers]

I checked the gas manifold for cobwebs and cleaned out the orifices as well In case someone was going to suggest that…

 

[1poolman1]

If there is an observation port, I have no clue as to where it'd be. The sequence I'm getting is as follows.
1. I call for heat
2. The blower starts
3. After about 10-15 sec, I hear clicking (I put my hand on the gas valve and definitely felt some sort of clicking/vibration,) as well as the green 'heat" light on the front display lights up but just for a split second and then the cycle starts all over again. After the third attempt, I get the "IF" code.

On a side, when the heater was functioning, I always would smell gas when it ignited. Now when I attempt to ignite it there is no smell at all which makes me suspect that it's the gas valv.e

How do I check if the gas valve is working, or if it's stuck?

Gas valve may be bad if it is "buzzing." A true check requires a manometer to watch for a pressure drop as the main valve opens. Click/buzz with no drop in pressure is a bad valve.
But, please, check that any valve before the heater in the gas line is open. Have been called out to replace two heaters over the years where no one ever checked that the gas cock was closed. One was at the meter itself, far away and the other hidden by bushes so wasn't seen.
The results posted of your tests don't point there, but the lack of "smell" with the boards replaced does.

 

[soundcheckers]

Just a quick update. The culprit was indeed the gas valve. It wasn't easy getting the old valve off, but after trying a few different pipe wrenches, I was able to get it out and get the new one in, and it fired right up!
Thanks so much to all of you that took the time to help me out. You saved me a lot of $$ and stress! I hope my next error code is a little easier to diagnose!