Starite 400na won't light

[rpoldervaart]

I have a 15 year old Starite 400na heater that won't light. This is hooked up to my Aqualogic PS8. A year ago, the pool heater started coming on at random times, so I disconnected the heater until I could fix it. I figured out the keypad membrane was leaking and the control board was damaged. Recently, I replaced the control board and keypad.

Now, when I turn the heater on, I hear the blower come on for a few seconds, I hear a click and smell some gas, and then a click as I would expect the heater to light, and I don't get a flame. After a few more seconds, the blower stops and the AFS light comes on. I think the AFS light is a red herring because the blower basically stops and that stops the air flow. Until the blower turns off, no service lights are on.

I just changed the igniter, and still the same thing. I checked the ohms on the igniter and it was something like 72.4, so I assume that's good. Last year, I took a lower bolt out of the heater manifold and had no water come out, so I assume there is no water in the heater.

What's left? How do I check the gas, or who do I call to check the pressure? What else should I check?

Thanks in advance!!

Robert

 

[ps0303]

I see you checked the ignitor for an ohms reading but have you used a meter to see if the ignitor is actually getting the power it needs to light up?

 

[rpoldervaart]

No I haven't checked power coming to the igniter. What will be the voltage I should look for? Will it be constant, or just for an instance?

 

[1poolman1]

Voltage should be in the 100v + range. It is constant until the gas valve opens. Voltage off, valve opens. You can hear that happen. If you don't have that voltage you likely need a new Fenwal device.

 

[rpoldervaart]

Thank you! I will check the voltage tomorrow, or maybe today at lunch. Do I check voltage across the two leads going to the igniter, or one lead to ground?

 

[ps0303]

Disconnect the igniter from the two leads and then connect one lead from the meter to each wire. You should see 120V when the signal is sent to the igniter.

 

[JamesW]

You can check the amperage to see if the ignitor is actually using power.

Pentair 400 Heater not igniting, no errors, everything visually working

Hi guys, I've spent a good amount of time troubleshooting this myself and am out of ideas. Heater has been working fine for months with no problems. I realized it was not heating one day and it has not ignited at all since then. It goes through the ignition process, everything appears to be...

www.troublefreepool.com

 

[rpoldervaart]

I checked the voltage this weekend. When I put the meter across both leads going to the igniter, I would see about 20v (before even trying to start the heater), and it never goes up to 120v during the ignition cycle, and really never moves.

I tried testing the S2 terminal on the Fenwal device and the other probe to ground. I did see the voltage go up to 122 during ignition cycle, a couple of clicks and then voltage drops down.

In both cases, I end up with the light on the Fenwal device flashing 3 times.

Surprisingly, when the heater is not trying to start, I'm seeing some voltage at both the igniter leads and the S2 terminal on the Fenwal. Using the leads going to the igniter, it's about 20v and never goes up. Using the S2 and ground, the reading is about 90v and goes up to 122v when it tries to start. It's a new meter, so maybe the auto ranging is not really showing 20 and 90 volts, but regardless, the S2 does show it going up to 120, and testing at the leads going to the igniter does not show the volts going up to 120.

So, does this mean I need to get a new Fenwal device?

I'll try to add a couple of videos.

Probes inside connector leads going to igniter:


And checking voltage at the Fenwal S2 and ground:

 

[ps0303]

If you are not seeing 120V on the leads from the fenwal, then the fenwal is not sending the voltage down tot he igniter.

 

[JamesW]

Your meter can measure current.

Put it inline and check to see how many amps are going to the ignitor.

 

[JamesW]

You have the red plug in, which means that the supply voltage should be 240 volts.

The ignitor uses 120 volts.

For a 240 volt supply, the Fenwal pulses the voltage to simulate the 120 volts needed for the ignitor.

This pulsed voltage is not going to read correctly with a non “True-RMS” meter.

As the ignitor is supposed to get voltage, S1 and S2 should get 120 volts AC.

You can see where the S1 and S2 gray wires connect to the ignitor.

You can measure the voltage at the gray wires with a true RMS meter or you can measure the current by clamping around one of the gray wires or by putting your meter inline with one of the gray wires.

 

[JamesW]

To get a good measure of the voltage, you need to check the voltage at the red dots on both sides of the ignitor with a true RMS voltmeter.

Also, measure amperage with a true RMS clamp ammeter or an inline true RMS meter.

 

[JamesW]

You say that the AFS light comes on, which indicates an air flow fault.

Last year, I took a lower bolt out of the heater manifold and had no water come out, so I assume there is no water in the heater.

Check this again.

Pull out the voltage selector plug and check to make sure that it is not damaged.

Do not install the 120 volt black plug.

Check the voltage from L1 to L2 and then from S1/240 to S2.

Check to see if you are getting 24 VAC at the TH terminal when the ignitor should come om.


Here is an example of checking the amperage at the ignitor with a clamp ammeter.

As you can see, the amperage begins to climb shortly after the blower starts.

The blower starts and then the AFS (Air Flow Switch) should close.

As soon as the AFS closes, the TH terminal gets 24 VAC, which closes the relays from the L1 to S1 terminal and the L2 to the S2 terminal, which sends power to the ignitor.

If you are getting an AFS warning light, then maybe there is an air flow problem or the AFS is going bad.

If the AFS is intermittent, then that can interrupt power to the ignitor.

Check the AFS to make sure that it is securely closing and staying closed.

 

[rpoldervaart]

Thank you everyone! James, I have a clamp on amp meter. After multiple tests, I got 0 amps on either of the leads going to the igniter connector (with it plugged in to the igniter of course), so no juice running through it. To test my amp meter, I clamped it around one of the wires powering the heater and got 4-5amps during startup (blower running).

I checked the amps the same as the video, with my clamp amp meter.

Since it looks like I need a new Fenwal controller, mine has cat no 35-662903-003 on it, but everything online seems to be 35-662944-013. Is this 662944-013 a correct replacement part?

James, reading your last post -
Where is the voltage selector plug? I don't remember that. Is that the white plug S1/120, L1, L2, S2?

I just put the covers back on. I'll do the other tests tomorrow.

As far as the AFS, if I turn it on after sitting for a while, the blower comes on, goes through the startup sequence, fails to ignite, and the blower turns off. The AFS light comes on after the blower turns off and there's no more air flow. The fenwal light usually flashes 3 times after this.

If I turn the heater off and then on again (with the PS8 controller), the AFS light might come on before the blower even comes on. It's like it's remembering from the last startup. Is there a timer that remembers the AFS light and locks out the heater for a period of time? Can I easily reset this? I've been trying to remove power, waiting 10-20 seconds and trying again.

But again, the AFS light usually comes on when there is genuinely no air flow, like after the blower shuts off or on subsequent startups when the blower hasn't even started yet. I can blow into the air tube and turn the AFS light off.

 

[JamesW]

Where is the voltage selector plug?

Ignition Control Module 42001-0052s, Replaced by 476223 - INYOPools.com

42001-0052S - IGNITION CONTROL MODULE (42001-0052S)

www.inyopools.com

 

[JamesW]

Are you getting 24 VAC at the TH terminal a few seconds after the blower starts?

Check the voltage from L1 to L2.

Check the voltage from S2 to S1/120 and from S2 to S1/240 after the blower starts.

 

[JamesW]

After a few more seconds, the blower stops and the AFS light comes on.

If the AFS comes on, then there is probably an air flow problem or a failing AFS.

I don't think that the AFS LED is going to light if the system turns off the blower because the system will not expect the AFS to be closed after the blower is turned off.

 

[JamesW]

If your heater is correctly connected to 240 Volts AC, the Ignition Control Module (ICM) will convert the 240VAC to an intermittent pulse to the ignitor.

Digital meters don’t read this type of signal well. (An analog meter will give a better reading than a digital meter).

If the ICM is bad, your voltmeter will read either 0 VAC or 240 VAC.

If your ICM is good, your meter will read some voltage between 0 and 240 VAC.

Exactly what reading you get will depend on the meter, but with a good ICM, the reading won’t be 0 VAC or 240 VAC, but somewhere in between.

 

[JamesW]

If I turn the heater off and then on again (with the PS8 controller), the AFS light might come on before the blower even comes on.

Maybe the AFS is sticking closed.

If the AFS is closed before the blower is on, then the system will lock out.

 

[rpoldervaart]

When I get home tonight, I will pull out the red 240 voltage selector plug and see if it is damaged. I don't have a 120 black wired plug.

I'll do the other tests that you suggested.

Maybe I should buy a air flow sensor and the fenwal, replace the air flow sensor first to see if that resolves the problem. If not, then install the new fenwal module.