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

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@JamesW

Here we have the manometer hooked up to only the inlet side. There is no drop in gas pressure as the unit cycles. I need to get another fitting to test the pressure differential Accross the block. Anything stand out to you sir?

 
Is the gas valve switch On or Off (red arrow)?

Are the units in KPa or inches of w.c?

It looks like Kpa.

9.8 KPa is 39" w.c.

If the pressure is not dropping at all, the valve is not opening.

Is the valve getting voltage?

Don't worry about the differential if the gas valve is not opening.

1663088797796.png
 
JamesW said:
Is the gas valve switch On or Off (red arrow)?

Are the units in KPa or inches of w.c?

It looks like Kpa.

9.8 KPa is 39" w.c.

If the pressure is not dropping at all, the valve is not opening.

Is the valve getting voltage?

Don't worry about the differential if the gas valve is not opening.
Click to expand...

Gas valve is On.
Switch is On.
Unit is in KPa
The pressure does not drop.
I will check for voltage to the unit and report back (however it has started to rain, so it might be tomorrow if this rain doesn't stop).
 
9.8 KPa is 39" w.c. (1.4 PSI), which is way too high.

Do you have a regulator before the heater?

Maybe you have a 2 psi line with no regulator, which might have damaged the gas valve.
 
Last edited:
Looks like you have 2 psi to this regulator.

Maybe the regulator has failed and the pressure has been too high causing the valve to be damaged?

Check for 24 VAC to the gas valve.

What is the aluminum foil thing?

Check the inlet gas pressure in inches of water column and fix if over 14" w.c.

Once the pressure is fixed, check for 24 VAC to the gas valve.

1663094212957.png
 
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I am getting this same result from both terminals on this block. The 24v turns on, then appears to turn off after (probably lack of ignition).

I smell nothing out the exhaust.
The foil is for the regulator going to my grill, it gets moisture in the vent trap, and stops working.

I will test again the measurement Accross the block to see if any gas at all flows. From all this, you would think gas would flow. But maybe the static pressure is to high. So I will check that again too.
 

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Checked static pressure again…this time in Inches of WC and sure enough, I am seeing 40” of WC.

Bought the wrong 1/8” adapter so I will need to check again tomorrow ‘Accross’ the gas block.
 

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IanB22 said:
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?
Click to expand...
What was this about?

Did they check the gas pressure?

What pressure did they get?

Why are they saying that the pressure is good at 40" w.c?
 
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The first thing you need to do is get the gas pressure to be in the correct range.

Then, you can see if the heater works.

If not, you can check the gas pressure as the heater tries to fire to see if it drops or stays the same.

If it doesn't drop, check the voltage going to the valve.

If the voltage is good and the pressure doesn't drop, the valve is bad.

If the pressure drops about 0.5" to 2" w.c, the valve is opening.

If the pressure drops below the minimum, the gas supply is bad.

If the voltage is bad, you can check further upstream to see where the voltage stops.
 
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Since you have a regulator, the question is, did the regulator fail or has it always been the wrong pressure because it is the wrong regulator?

Can you show all writing on the regulator?

If it is the wrong regulator, and the gas valve is damaged, I would expect the plumber to replace the regulator and the gas valve at their expense.
 
@JamesW - Gas supply issue is now fixed. I have a consistent 8 inH20 at the input side of the block.

As to the electrical issue in the gas block.
Here is a video of the voltage I get when I connect my multi-meter as asked.
I get 1.478 volts

1665080972968.png
 
The switch was the issue!!!! @JamesW for the WIN!
The bypass went in...and BOOM fully lit up and pumping heat into my hottub as we speak.
First world problems, but still....feels goooooodddd.....

Now, do I leave it like this?
Does the switch do anything functional?

 

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