JBJ True Temp Probe

SandJ · Oct 20, 2017

I think the temperature probe is bad on my JBJ True Temp Controller. The display shows random numbers every second.

It looks like the cheapest probe is $25. Does anyone know of a cheaper probe that will work with the controller? I don’t mind splicing wires if necessary :0)

saltyfilmfolks · Oct 20, 2017

What type of connection is it? Do you know it's a two wire or three wire?
I bought a bag in bulk for mine. In fact , that's how I found out there was a difference. I now have a bag of unused 3 wire probes still in the garage.

SandJ · Oct 21, 2017

saltyfilmfolks said:
What type of connection is it? Do you know it's a two wire or three wire?
I bought a bag in bulk for mine. In fact , that's how I found out there was a difference. I now have a bag of unused 3 wire probes still in the garage.

@saltyfilmfolks it is a two wire probe, with the end having a square and round connector.

saltyfilmfolks · Oct 21, 2017

SandJ said:
@saltyfilmfolks it is a two wire probe, with the end having a square and round connector.

Poke amazon. The connector is the only hang up.
I got my two wire from eBay and it came with mostly square connector.
Mine were $10 for five of them but came slow boat.
If you don't mind splcing is an easy fix.

https://www.amazon.com/SUNKEE-DS18B20-Temperature-Sensor-DS18B20DS18B20/dp/B008HODWBU

Reef 450 · Oct 21, 2017

SandJ said:
I think the temperature probe is bad on my JBJ True Temp Controller. The display shows random numbers every second.

It looks like the cheapest probe is $25. Does anyone know of a cheaper probe that will work with the controller? I don’t mind splicing wires if necessary :0)

Dude that thing almost crashed my tank. It failed several times. I called JBJ they said I need to replace the probe every 3 months. For a device so costly I think that it’s unacceptable. I recommend an apex or a reef keeper and a cheap heater.

SandJ · Oct 21, 2017

Reef 450 said:
Dude that thing almost crashed my tank. It failed several times. I called JBJ they said I need to replace the probe every 3 months. For a device so costly I think that it’s unacceptable. I recommend an apex or a reef keeper and a cheap heater.

Ugh, sorry to hear that. It worked great up until the probe failed...and when the probe failed I discovered my heater had also failed at some point and was stuck in the on position ;Nailbiting so the Tank was at 82 degrees.
And I agree, $25 every three months seems a little excessive. I can buy the entire True Temp controller and heater for $50, so why $25 formjust the probe.

SandJ · Oct 21, 2017

saltyfilmfolks said:
Poke amazon. The connector is the only hang up.
I got my two wire from eBay and it came with mostly square connector.
Mine were $10 for five of them but came slow boat.
If you don't mind splcing is an easy fix.

I will look around for one...if you happen to see the correct probe would you mind linking it?

saltyfilmfolks · Oct 21, 2017

SandJ said:
I will look around for one...if you happen to see the correct probe would you mind linking it?

Sure. If can put up a pic and tag me.

saltyfilmfolks · Oct 21, 2017

See if yours is a molex connector. Is common and help you find one quicker

SandJ · Oct 21, 2017

@saltyfilmfolks this is the connector end on the probe. Thanks for your help!

https://leeselectronic.com/en/product/41401.html

saltyfilmfolks · Oct 21, 2017

SandJ said:
@saltyfilmfolks this is the connector end on the probe. Thanks for your help!

https://leeselectronic.com/en/product/41401.html

Score!

SandJ · Oct 21, 2017

saltyfilmfolks said:
Score!

How do I find a probe that will work? Will any two wire probe work, I just need to splice an end onto it the will plug into the controller?

saltyfilmfolks · Oct 21, 2017

SandJ said:
How do I find a probe that will work? Will any two wire probe work, I just need to splice an end onto it the will plug into the controller?

Yup. But def do a little digging if your not confident. I'm sure there's one with it on.

My temp controller uses a tightening screw , so I had to cut the end off and strip the wire to make it work for me. Just note the polarity.

I have an instant read cooking thermometer I use the check the temp.

Ranjib · Oct 22, 2017

bummer... a standard ds18b20 temperature probe costs around 15$ and has +/- 0.5 degree Celsius error rate, one would expect bit better performance from expensive gadgets :-(

saltyfilmfolks · Oct 22, 2017

Ranjib said:
bummer... a standard ds18b20 temperature probe costs around 15$ and has +/- 0.5 degree Celsius error rate, one would expect bit better performance from expensive gadgets :-(

Manufacturers take advantage of manufacturers names sometimes sadly.

Jay Cahow · Dec 27, 2017

I have a dozen of these JBJ Heater controllers that I have purchased over the last half dozen years and I have had a few of the temperature probes go wacky and produce inaccurate results. Most of them have never failed and the ones that have seem to be in the same tanks. I wonder if the large fish in those tanks might be doing something to them.

Anyways I have found the cheapest place to purchase them is from JBJ directly. I think I paid a little over $30 for a pair the last time I contacted them over the phone. No one from there has ever mentioned anything to me about replacing them on a regular basis. I am lucky in that all my tanks are in two separate rooms and they all have these heater controllers. When I walk in the rooms I can see all tanks temperatures at a glance and because they are all set to the same point it is easy to see if one is reading different than the others.

I need to order some myself as I just noticed one is going bad, it was jumping all around but I got it working again now by playing with the lead in the tank. It is consistently reading a couple of degrees low but I just adjusted the controller to compensate for now. I will call them tomorrow and see what they are selling them for direct now.

Ranjib · Dec 27, 2017

Jay Cahow said:
I have a dozen of these JBJ Heater controllers that I have purchased over the last half dozen years and I have had a few of the temperature probes go wacky and produce inaccurate results. Most of them have never failed and the ones that have seem to be in the same tanks. I wonder if the large fish in those tanks might be doing something to them.

Anyways I have found the cheapest place to purchase them is from JBJ directly. I think I paid a little over $30 for a pair the last time I contacted them over the phone. No one from there has ever mentioned anything to me about replacing them on a regular basis. I am lucky in that all my tanks are in two separate rooms and they all have these heater controllers. When I walk in the rooms I can see all tanks temperatures at a glance and because they are all set to the same point it is easy to see if one is reading different than the others.

I need to order some myself as I just noticed one is going bad, it was jumping all around but I got it working again now by playing with the lead in the tank. It is consistently reading a couple of degrees low but I just adjusted the controller to compensate for now. I will call them tomorrow and see what they are selling them for direct now.

You should check for stray voltage on the tank where temp probes go bad frequently.

Jay Cahow · Dec 27, 2017

"You should check for stray voltage on the tank where temp probes go bad frequently."

I am not sure what you mean here. Stray voltage leaking from the probe itself as I have no other electrical devices in the water.

I have over a dozen large fresh water tanks that all use external canisters with inline external heaters. So there is nothing electrical in any of the tanks to cause stray voltage unless you mean it might be coming from the temperature probe itself.

When I look at the probes that have previously failed (I jhve a few laying around) it seems like they cracked or are torn where the lead wire enters the probe. My guess is that the large cichlids are biting or pulling on the probes underwater and over time they cause the probes to fail. The suction cups on the probes are worthless after awhile so they come unattached from the glass and just hang in the back of the tank where the fish can yank on them. It is only a theory and they may just be breaking down after they have been so long under water.

I sent JBJ an email asking if they still sell directly to customers and if so at what price......................

Jay Cahow · Dec 27, 2017

"You should check for stray voltage on the tank where temp probes go bad frequently."

I am not sure what you mean here. Stray voltage leaking from the probe itself as I have no other electrical devices in the water.

I have over a dozen large fresh water tanks that all use external canisters with inline external heaters. So there is nothing electrical in any of the tanks to cause stray voltage unless you mean it might be coming from the temperature probe itself.

When I look at the probes that have previously failed (I jhve a few laying around) it seems like they cracked or are torn where the lead wire enters the probe. My guess is that the large cichlids are biting or pulling on the probes underwater and over time they cause the probes to fail. The suction cups on the probes are worthless after awhile so they come unattached from the glass and just hang in the back of the tank where the fish can yank on them. It is only a theory and they may just be breaking down after they have been so long under water.

I sent JBJ an email asking if they still sell directly to customers and if so at what price......................

Ranjib · Dec 27, 2017

Jay Cahow said:
"You should check for stray voltage on the tank where temp probes go bad frequently."

I am not sure what you mean here. Stray voltage leaking from the probe itself as I have no other electrical devices in the water.

I have over a dozen large fresh water tanks that all use external canisters with inline external heaters. So there is nothing electrical in any of the tanks to cause stray voltage unless you mean it might be coming from the temperature probe itself.

When I look at the probes that have previously failed (I jhve a few laying around) it seems like they cracked or are torn where the lead wire enters the probe. My guess is that the large cichlids are biting or pulling on the probes underwater and over time they cause the probes to fail. The suction cups on the probes are worthless after awhile so they come unattached from the glass and just hang in the back of the tank where the fish can yank on them. It is only a theory and they may just be breaking down after they have been so long under water.

I sent JBJ an email asking if they still sell directly to customers and if so at what price......................

Ah..ok,.
I meant stray voltage from other equipment (heater, return etc). I have noticed my probes some time behave badly when its close to other equipment... but then again its one of the very many ways the temp probe fails....