Pentair Mastertemp 400 - No Ignition, No Error lights, tested a few things and need help.

[IanB22]

Well it's been a few years since I was back on the TFP.
Because my pool(s) have been trouble free after learning so much!

However, I have been working on my Pentair Mastertemp 400 for about a day now - between research and video's and trying to troubleshoot what's actually wrong before I start replacing parts.
Here are 3 videos of the symptoms with poor narration from me.

Clearly there is power, and there appears to be no error lights (this was taken during cold start-up).
It was working fine about a week or so ago, and there is no rodent damage.
I also peered down through the exhaust to see if there was water in the tub, it appears there isn't any (thankfully!)

I checked the Igniter and the ohms reading when cold is 87, I realize this is close to the allowable maximum.
I have not yet removed the ignitor for a visual inspection.

Hoping there are some true 'heater' whisperer's here that can give me a clue. Thanks!

 

[Poolbreh]

Do you smell gas? You would need a manometer to confirm proper gas pressure. You can pull igniter and inspect for small cracks.

 

[ajw22]

Why did you have the gas off?

If you have air in the gas line it make multiple start cycles before the air is purged from the gas line.

 

[IanB22]

@Poolbreh - I smell a very faint amount of gas. I think (because I have had gas problems to this regulator - and it also runs my grill) I am going to have a plumber ensure the gas pressure and regulators are 100% before I start replacing parts.

@ajw22 - I had the gas off as a precaution when I was troubleshooting. In hindsight this wasn't really needed as I wasn't touching the gas-line anyway. I did not know the start cycles would need to purge air etc, so we'll confirm the gas pressure first, then confirm anything else after that.

 

[IanB22]

All - Gas pressure going to the Pentair is perfectly fine.
soooo it's on to the next idea you'll have. Am I thinking ignitor?

 

[Poolbreh]

Yes pull ignitor and inspect for cracks and scale. What was the wc going into the heater?

 

[IanB22]

A couple photo's of the igniter and it's resistance.
It is within spec... so I guess that puts us to keep looking??
Or do I just not trust it and send away for a new one... I could heat it up with a torch and see if resistance changes?
@Poolbreh

 

[JamesW]

Check the voltage and amperage going to the ignitor during call for heat.

 

[JamesW]

Apply 120 VAC directly to the ignitor wires to see if it gets hot.

Check the amperage as the voltage is applied.

Check the Fenwal for any Diagnostic indicator LEDs.

https://www.pentair.com/content/dam/extranet/nam/pentair-pool/residential/heaters/mastertemp/manual/Manual-MasterTemp-472592-English.pdf

 

[JamesW]

Look into the hole where the ignitor goes to see if you see water.

Remove one bottom manifold bolt to see if you see water.

 

[JamesW]

All - Gas pressure going to the Pentair is perfectly fine.

What was the inlet static and dynamic reading?

Static is before call for heat.

Dynamic is on call for heat.

During call for heat, the pressure should drop some ( 1" or 2 " wc), but not a lot.

If it drops some, the valve is probably opening.

If it does not drop at all, the gas valve is not opening.

If it drops below the minimum, you have a supply problem.

 

[IanB22]

It has now started to pour with rain... I will get to my homework tomorrow.

 

[IanB22]

Check the voltage and amperage going to the ignitor during call for heat.

@JamesW - Checked the voltage and I am seeing 98v to 102 volts going to the igniter. See first video attached.
Second video show's the ignitor heating up with a temp gun on it. Looks pretty solid to me.

 

[JamesW]

If the supply is 230 volts, then the voltage is modified down to 120 and it is not a clean sine wave so the voltage won't read exactly 120 volts.

If the supply is 120 volts, then it should read a clean 120 volts.

 

[JamesW]

Check the current with your clamp ammeter.

 

[JamesW]

IMPORTANT! READ ME FIRST!!

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.

https://www.pooltek.com/wp-content/uploads/2017/02/Heater-PentairMastertemp.pdf

 

[JamesW]

Apply 120 VAC directly to the ignitor wires to see if it gets hot.

Check the amperage as the voltage is applied.

Check the Fenwal for any Diagnostic indicator LEDs.

 

[IanB22]

Look into the hole where the ignitor goes to see if you see water.

Remove one bottom manifold bolt to see if you see water.

@JamesW - Here is the boroscope into the tub. Looks dry as a bone to me.
Also see the second video for the Ignitor heating up correctly.

 

[IanB22]

Finally my last test for today.
@JamesW - This is a view of the thermistor and the error code I got when ignition lockout occurred.

I can now also see that I am wired for 240 not 120, so that means I won't have a clean 120v going to the ignitor (I think)
Also, I do NOT smell gas, even when I put my head directly in the line of the exhaust, I can not smell gas (like I would on a gas grill etc...)

Manometer is on it's way, so I can check gas through the valve.
Thank you everyone who is helping so far.

 

[JamesW]

Looks like a gas supply issue.

Are all of the gas valves on including the switch on the heater gas valve?