Hayward 400fdn LO error

Jul 21, 2015
78
Long Island, NY
Pool Size
44000
Surface
Vinyl
Chlorine
Liquid Chlorine
So I opened my pool on my on for the first time. When I go to run the heater, I get an LO error. My first guess is that I didn't turn the gas on correctly. I took a picture of the gas line. It's hard to tell, because there isn't much handle left, but does that look like I have the line open correctly?
 

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LO indicates low water pressure. Was pump running? Valves set correctly?

See Hayward 400fdn repair vs. replace
Yes, the pump is on. I know the heater goes to LOb when the pump is off, or even when flow isn't great because the filter needs to be backwashed. However, now the pump is running well and the heater is on "bo", which is the normal symbol. It is only after I call for heat, and I hear clicking and the fan run, that it goes from "bo" to "LO".
 
Thanks for all the help on this. Call me stubborn, but I still think it may be a gas issue, based on previous experience. Also. When I turn the pump on, the heater good from LO to bo, and only goes back to LO when I call for heat, so I don't think it is a pressure issue, despite what the manual says.

The last time I had this issue, I made a service call, and he found a spider web. I tried to check for the web, but I couldn't remove the gas manafold after removing the four retaining screws. It seemed like it was still attached to the gas valve, and I want sure how to remove it. Does anyone have good instructions in removing the gas manifold, so I can check it for webs?
 
I’d be going with a flow problem, either sensor or actual water flow problem.What pump do you have and what speed are you running it when calling for heat? I have to run my pump on 2 otherwise I’ll get the Lo fault if on speed 1.

Salty
 
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