Brand New Hayward H500 not workin

[josephny]

I bought a replacement for a broken H500 in the Fall and just installed it today.

The system fails with an A0

I've read that A0 means the vacuum sensor is not reading a vacuum -- either the fan motor is not creating the vacuum or the sensor is no good.

The fan is spinning nicely, and the unit is brand new. Totally clean inside, vacuum and pressure hoses nicely pushed on to both the fan housing and the sensors.

It's been too long to go back to the vendor.

I was hoping that because the propane gas pipe sat turned off all Winter, maybe it just needed time, but it's been a couple of hours of trying to make this work.

What should I do?

Thank you!

 

[1poolman1]

Make sure no rodent holes in the tubing. It happens.

 

[JamesW]

What is the supply voltage?

It looks like the old one was connected to 120 volts.

If the input voltage is 120 and the heater is set to 240 volts, the fan will run too slow.

Note: Do NOT put 240 volts on a heater set to 120 volts or the heater will be damaged.

 

[josephny]

Wow!

The heater was being fed 120v (1 hot, 1 neutral).

When I changed the plug on the motherboard, I could hear the fan spinning much faster.

So that fixed the A0 error.

But now, immediately upon power up, CE flashes and then changes to 5F (could be SF).

Googled it and found it 5F indicates a faulty temperature sensor.

But, seeing as I've messed this up from the get-go, perhaps I'm missing something else?

Is the conversion from 240 to 120 more than the single jumper-plug on the control board?

Any other ideas?

Thank you!

 

[JamesW]

The conversion should be just the plug.

The sensor wiring might be loose.

Check all wiring.

Is the water flow good?

Do you have an external bypass?

https://www.hayward-pool.com/assets/documents/pools/pdf/manuals/UHS-Service-Installation-011717-RevT.pdf

 

[josephny]

The conversion should be just the plug.

The sensor wiring might be loose.

Check all wiring.

Is the water flow good?

Do you have an external bypass?

View attachment 409868
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https://www.hayward-pool.com/assets/documents/pools/pdf/manuals/UHS-Service-Installation-011717-RevT.pdf

Wiring from thermistor to connector on control board appears fine.

Water flow is at 90gpm.

I do not have an external bypass.

I've ordered a new sensor. Seems Hayward changed the sensors they use from FDXLTER1930 to FDXLTER1931 (so it will take a few extra days to get to me; and to know if the problem really is a bad sensor).

Anything else I can do or check?

 

[JamesW]

Anything else I can do or check?

Nothing else I can think of.

Seems odd for a sensor failure for a brand new heater.

Maybe post a video of the startup.

 

[josephny]

I just tested the resistance at the control board side of the wire coming from the sensor and both black-red1 and black-red2 are both just under 13kohms.

From what I can find online, that corresponds to about 66*f, which is the water temp.

Yet I still have an SF error.

I will take a video, but in the meantime, upon power up I get CE for about 1 second then it changes to SF.

Is there such a thing as a factor reset for the control board?

 

[josephny]

I'm probably grasping at straws, but it is okay that there is nothing connected to the SEL. SWITCH connector on the control board?

(I know the ignitor connector is empty -- that's been remedied.)

 

[josephny]

If I understand correctly, the resistance tests shows that the sensor is good. That means it could be the control board. Is there anything else it could be?

Here are a couple of videos.

Ignore the flickering -- it doesn't flicker in real life, must be refresh rate thing

 

[JamesW]

I just tested the resistance at the control board side of the wire coming from the sensor and both black-red1 and black-red2 are both just under 13kohms.

Disconnect the thermistor from the board and measure red/black 1, red/black 2 and red/red and report the exact numbers.

 

[josephny]

I must have misread the readings the first time.

This time:
RED1-BLACK is 3300 ohms
RED2-BLACK is 105 ohms

This is clearly not what it's supposed to be. Maybe I'm in luck and the sensor really is malfunctioning.

 

[JamesW]

Try a new sensor.

Maybe ask Hayward to send you one as a warranty claim.

I'm not sure why they put two in the same sensor anyway.

 

[josephny]

Already ordered (I don't have the time/energy to deal with a warranty claim).

Thank you!

 

[josephny]

Just installed a new thermistor and the unit fired up just fine.

Thank you very much!