Sensor Failure Message

[evanwellens]

So we had 3 solid days of rain , was looking forward to swimming and warming up the pool. Went to turn the heater on ( raypak 399K) and the display was flickering a bit ( which happens time to time when extreme wet ). What's new is the message comes up Sensor Failure. Could this just be a matter of things are wet ? Or truly the sensor decided to go ? Or something else ?

Any suggestions on troubleshooting ?

0 new items by Evan Wellens

photos.app.goo.gl

 

[1poolman1]

So we had 3 solid days of rain , was looking forward to swimming and warming up the pool. Went to turn the heater on ( raypak 399K) and the display was flickering a bit ( which happens time to time when extreme wet ). What's new is the message comes up Sensor Failure. Could this just be a matter of things are wet ? Or truly the sensor decided to go ? Or something else ?

Any suggestions on troubleshooting ?

0 new items by Evan Wellens

photos.app.goo.gl

It could be something is wet, but more likely one side of the temperature sensor has failed. Its the only sensor in that unit. They are a dual sensor in the one unit (notice the three wires). The readings have to agree or you get that error message and the heater won't work. You could try drying the board off, but will probably have to replace the sensor. Easy job.

 

[evanwellens]

It could be something is wet, but more likely one side of the temperature sensor has failed. Its the only sensor in that unit. They are a dual sensor in the one unit (notice the three wires). The readings have to agree or you get that error message and the heater won't work. You could try drying the board off, but will probably have to replace the sensor. Easy job.
View attachment 602925

Many thanks , part is on the way !!

 

[evanwellens]

OK went back to check ,now says rollout sw open. Turned everything off waited a moment , still same message.

 

[evanwellens]

OK from what I gather the rollout is a safety next to the gas inlet to prevent bad things... Multimeter shows no continuity. So I guess it's a sacrificial fuse , so is what you are saying is the temp sensor is not keeping the heat in check , so the roll out blew as a safety ? Hence I need a new roll out as well I would assume ?

Some picts to show what I am seeing
Rollout ? New item by Evan Wellens
under burners ,doesn't seem soot filled. New item by Evan Wellens
Discolored interior ( not sure if this is new or old TBH ) New item by Evan Wellens


So new temp sensor on the way , and new roll out.

Any other advice ?

 

[1poolman1]

OK from what I gather the rollout is a safety next to the gas inlet to prevent bad things... Multimeter shows no continuity. So I guess it's a sacrificial fuse , so is what you are saying is the temp sensor is not keeping the heat in check , so the roll out blew as a safety ? Hence I need a new roll out as well I would assume ?

Some picts to show what I am seeing
Rollout ? New item by Evan Wellens
under burners ,doesn't seem soot filled. New item by Evan Wellens
Discolored interior ( not sure if this is new or old TBH ) New item by Evan Wellens


So new temp sensor on the way , and new roll out.

Any other advice ?

Roll out switch (fuse) blows when flame gets out of the combustion chamber, it isn't related to the sensor.
Sensor just tells the board what the temp of the in-coming water is so the board "knows" whether to fire the heater or not.
Flame-rollout is usually caused by high wind during heater operation, especially if there is a lot of growth around the heater or a high wall/fence very close, or a sooted heater from low gas pressure, or a lot of leaves on the top of the heater under the metal top, or . . .
Yes, your heater can operate properly for years under those conditions, but something can change and force a downdraft, pushing the flame out.

 

[swamprat69]

Photo is indicative of rollout occuring almost wholly on the right side of the burners as indicated by rusting of the front plate of the combustion chamber (opposite of the side that the rollout switch is mounted). Observation of the burner flames with the heater running to make sure that all burner flames are 2 shades of blue with an inner and outer cone to the flame may help in diagnosing the problem.

 

[evanwellens]

Photo is indicative of rollout occuring almost wholly on the right side of the burners as indicated by rusting of the front plate of the combustion chamber (opposite of the side that the rollout switch is mounted). Observation of the burner flames with the heater running to make sure that all burner flames are 2 shades of blue with an inner and outer cone to the flame may help in diagnosing the problem.

Seems from the photo something going on for a while ? Or just chance occurence ? I've never seen rollout , but I don't sit there all day and monitor.

 

[evanwellens]

So not temp sensor at all I imagine.. Easy enough to return. Bought a 2 pack of toll outs , just in case. Why they make it so hard to change and not resetable like I've seen on others.

Moving forward sounds like I should open up the top and inspect ? Maybe wash out the heat exchanger, in which case that requires me to remove burner tray ?

 

[1poolman1]

So not temp sensor at all I imagine.. Easy enough to return. Bought a 2 pack of toll outs , just in case. Why they make it so hard to change and not resetable like I've seen on others.

Moving forward sounds like I should open up the top and inspect ? Maybe wash out the heat exchanger, in which case that requires me to remove burner tray ?

The only other way I have seen (only once) that kind of damage and a roll-out switch blowing was when the refractory material that lines the combustion chamber was damaged. It had cracked at the front, behind the panel that is in that picture, and was allowing too much heat into the control area.
Heater was under warranty. Ray-Pak paid me to virtually rebuild it.

 

[evanwellens]

Tested the new rollout , still had sensor error . Installed new temp sensor and the heater would go into spark mode. So opened up the top and there was a huge mess twig, leaves and other organics. Not sure how it would get in there as I assumed running the heater burns up blockages , but cleared that up and vacuumed the heat exchanger. Voila , all worked well. Nice blue flames an no warmth near the rollout.. Thanks for all the info !!

 

[1poolman1]

Tested the new rollout , still had sensor error . Installed new temp sensor and the heater would go into spark mode. So opened up the top and there was a huge mess twig, leaves and other organics. Not sure how it would get in there as I assumed running the heater burns up blockages , but cleared that up and vacuumed the heat exchanger. Voila , all worked well. Nice blue flames an no warmth near the rollout.. Thanks for all the info !!

Since you can, for a short while anyway, keep your hand in the exhaust of a pool heater, that means that most anything above the heat exchanger won't reach combustion temperature, but it will dry out and block the exhaust. That will force the flame out of the box and blow the roll-out switch. It also can get the water temps in the exchanger too hot and cause issues with the sensor and hi-limit switches.

Depending on the heater's location in a yard, what is above it, some need cleaning at least yearly. Few installers/sales people will tell you that when installing as it can seem to be too much work.

 

[evanwellens]

Since you can, for a short while anyway, keep your hand in the exhaust of a pool heater, that means that most anything above the heat exchanger won't reach combustion temperature, but it will dry out and block the exhaust. That will force the flame out of the box and blow the roll-out switch. It also can get the water temps in the exchanger too hot and cause issues with the sensor and hi-limit switches.

Depending on the heater's location in a yard, what is above it, some need cleaning at least yearly. Few installers/sales people will tell you that when installing as it can seem to be too much work.

I seem to recall it used to burn stuff up.. Start of season a little smoke. But everything you said makes sense. Heater is in the woods making a challenging environment. Our first was destroyed by mice.