Insulating Water Temperature Sensor

[cnr1089]

For the last two years I have had my pool, it has really frustrated me that the water temperature (that decides if the heater should run) was very inaccurate. If the sun is out, it could be 5-10F different then what either the sensor in the Heat Pump thinks the water is, the sensor in the salt cell, or the temperature in an old fashion thermometer in the water.

The pool company says that the one I think is off is the most accurate and the rest are not very accurate. So, my pool says it is 87F right now, the heat pump says it is 80. The thermometer says 81, so I think that is probably the most accurate. That is a huge difference!

Anyways, I read the manual on my equipment and it says the temperature sensor should be installed with insulation around it (and 3” of the pipe) and painted white. I plan on bugging my pool builder (but it has been 2.5 years since they built the pool), but if they are no help, any suggestions for what I can use? Some link to something on amazon would be best (for insulating). I can’t paint white if necessary, but would be nice if I don’t have to.

Thanks!

 

[harleysilo]

Interesting, never considered the possibility that my temp sensor could be affected by sunlight heating up the pipes surface.

 

[jblizzle]

I just installed one too and saw that in the manual ... I have never seen one of the sensors actually insulated though.

I think the easiest would be to just buy a piece of the split pipe insulation. Put it over the sensor with a few zip ties and see if that helps ... maybe paint it too.

I may give it a go as well.
This is the stuff I was thinking if can find it large enough:

I see this is an option, although no sure about the fiberglass:

Maybe instead of painting white, just wrap it with aluminum tape or this insulated tape:

 

[ps0303]

I have never seen or heard of insulating the sensor and I live in FL where it's pretty darn hot these days. What system so you have?

 

[cnr1089]

Hayward Pro Logic
Here is the manual (or a similar one):


http://www.hayward-pool.com/pdf/manuals ... oOct08.pdf

"4. For maximum temperature accuracy, cover the sensor and 3”(6cm) of pipe on either side with insulation and white paint."

 

[ps0303]

Hmm, I've never seen it done.

 

[Prof100]

Mine is the same way. Early in the morning it reads dead perfect. If the afternoon is reads 5-10 high and the air temp reads 30-40 high. I just placed something over the sensor to block the sun.

 

[harleysilo]

Hmm maybe I'll add this to the lists of too try out, I need an in the pool therm for comparison purposes, mine broke. Seems logical if equiptment in sunny location.

 

[chiefwej]

I find my water temp readings are within a degree or so of my thermometer in the pool (SWG readings a different matter). This is true as long as water is moving in the pipe. When the pump stops it rises faster than the pool.

The sensor is inside the pipe and if water is flowing it will read the temperature of the water not the surface temperature of the pipe. If the water is not flowing, the standing water in the pipe starts heating up, and the readings reflect that. The temperature of standing water in a pipe are never going to tell you the temperature in the pool.

 

[JasonLion]

Mine is just like chiefwej's. If the pump has been running for more than a few seconds the temperature sensor reads perfectly, sun or no sun.

 

[Prof100]

The sensor Hayward uses is black and is installed by drilling a hole in the pipe and then securing with a hose clamp. The sun heats up the black outer portion and makes the sensor read high. I just re-plumbed my pump pad and plan to locate the new sensor under the pipe so the sun won't affect it as much.

 

[chiefwej]

The sensor Hayward uses is black and is installed by drilling a hole in the pipe and then securing with a hose clamp. The sun heats up the black outer portion and makes the sensor read high. I just re-plumbed my pump pad and plan to locate the new sensor under the pipe so the sun won't affect it as much.

That's the same sensor I have, but after installation it was wrapped with electrical tape then painted the same light tan color as the rest of my plumbing. We have some pretty hot sun here in Tucson, but it reads within a degree of my floating digital thermometer as long as the pump is running. I did have a problem but that was solved with a new sensor.

 

[cnr1089]

Ok, so I purchased http://www.amazon.com/gp/product/B000FP ... UTF8&psc=1 from amazon. It has made a huge difference. The temperature difference between the different sensors is now about 0-2F.