Chiller fan and compressor won't turn off.

[Airwalk1616]

Hello everyone I posted on the chiller forum thread that went dead a few years ago and unfortunately have not received an answer. But I own a 1/10 hp ecoplus water chiller from 2013 when it was the different shaped model then that is being sold now. Anyways I can have my set temp at say 70° and my chiller will continue to chill way past, clear down to 60 if I let it go long enough. It seems that my temperature sensor recognizes the cold temperature and engages the outlet on the back that is made for an external heater to warm the fish tank water in case this happens. It never used to do this and was working properly, as when it hit set temperature, the machine would stop rumbling and basically shut off until the temperature rose again and at that point started to chill again. I have taken the control board out and tested my relays, they are working and I'm really at a loss as to what could be the problem. I also removed the thermistor and did a test with a digital multimeter and at room temperature it was at 10,000 ohms and once I dipped it in ice cold water, it quickly rose to above 20,000. So I assume it is working but people have told me to change the thermistor but I can't help but think that if it's reading the correct temperature that it can't be that.
Does anybody have any idea what could be causing my fan and compressor to never turn off? I mean as soon as I plug it in before the light for chilling stops blinking the fan is blowing which is normally a 2 to 3 minutes standby mode in which once it becomes solid at that point it starts up. On a few other forums I've had a few people tell me to check NPN transistors or possibly the pin on the controller for the relay but I'm not quite sure what that means. If there's any HVAC or refrigeration technician's or anyone who just downright understands electrical temperature controllers how they work I would really appreciate some guidance on how to continue testing this control board. I have multiple pictures if you guys need to see anything. I just need to know how to back track from the fan motor and compressor to the controller hitting the set temp to shut off.

 

[Airwalk1616]

I sure wish ihavtats29 still was active on here!!!

 

[Linkfalcon]

Can u post pic of the controller and temp probes

have u called tech support and asked for the know values for the probes


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[Airwalk1616]

Yes. All the people I talk to at sunight supply just suggest using an external controller and I don't want to. I want it to work right. It's on a timer now for 1hr on and 2hrs off.

 

[Airwalk1616]

A few more

 

[Airwalk1616]

More

 

[Airwalk1616]

And I have checked the relays on the boards. Ones if the heater outlet on the back and ones for cooling. I set it to 66 as the temperature was at 68. Just to make a point to you the fan was blowing as soon as I plugged it in. But as the green Chiller light was flashing, as soon as it went solid I definitely heard and felt the relay click. And like I thought the opposite relay from before is now doing the same thing. Pole 1 is receiving NO power and 2, 3 and 4 all are. When the heater one clicked, it was poles 1, 2, & 4. so...

I just did it again and physically held the probes from the voltmeter on j9 and Pole 1 and as the green light was flashing as soon as it went solid it went straight to zero, I also then turn my set temp up to 69 and immediately that pole 1 received power again and as the red light was flashing once it went solid I heard the click and pole 3 went straight down to zero. So I'm assuming all of my relays are working. It has to be something else?

 

[Airwalk1616]

I checked the relays on the board one is for heating to turn on the outlet in the back of the machine as posted in the picture the other is for the cooling. I set it to 66 as the temperature was at 68. Just to make a point to you the fan was blowing as soon as I plugged it in. But as the green Chiller light was flashing, as soon as it went solid I definitely heard and felt the relay click. And like I thought the opposite relay from before is now doing the same thing. Pole 1 is receiving NO power and 2, 3 and 4 all are. When the heater one clicked, it was poles 1, 2, & 4. so...

I just did it again and physically held the probes from the voltmeter on j9 and Pole 1 and as the green light was flashing as soon as it went solid it went straight to zero, I also then turn my set temp up to 69 and immediately that pole 1 received power again and as the red light was flashing once it went solid I heard the click and pole 3 went straight down to zero. So I'm assuming all of my relays are working. It has to be something else?

 

[Airwalk1616]

This is what I mean by pole's 123&4.
Also, this is my unit. The older style.

 

[Airwalk1616]

The pins closest to the edge of the board are the zenon diodes pictured earlier.
The red arrows are the relay.

 

[Airwalk1616]

Can u post pic of the controller and temp probes

have u called tech support and asked for the know values for the probes


Sent from my iPhone using Tapatalk

let me know what ya think

 

[Linkfalcon]

I would replace controller the blinking light on most equip indicates it is in a lock out stage and will try to restart soon


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[Airwalk1616]

K... I can’t replace the controller. its not made anymore. There’s a component on the board that is malfunctioning, I just need help on how to pin point and find it.

 

[Airwalk1616]

And the blinking ligtnisnwhatnitsnsupposednto do. It’s startup mode that lasts 2-3 mins then starts to chill or heat. As soon as the light goes solid, the relays clicks.

 

[oldhead]

I'm guessing the are brought on by the relays instead of a contactor like a house a/c? If so I'm guessing they are fused in the closed position. Maybe look at the board behind the relays to see if it has burn marks. Did you happen to have a power surge lately?

 

[Airwalk1616]

I'm guessing the are brought on by the relays instead of a contactor like a house a/c? If so I'm guessing they are fused in the closed position. Maybe look at the board behind the relays to see if it has burn marks. Did you happen to have a power surge lately?

No I haven't had a surge any time recently. Also, I've checked the relays, their coils, and tested the thermistor probe and all is seemingly in working conditions.

 

[Gorgok]

So it heats or cools forever once it clicks on to that position? But is that random or can you control that?

If you can control it, then the brains probably work (and probe).

Then it may be as simple as a resistor that has given up (a pulldown on the coil control line). For the coil to release it should see under 1.2V (and over 9V to activate). You could measure that and see what it does.

 

[Airwalk1616]

The heater circuit onlypowers a 2 prong outlet in the back that an external heater plugs into that youdmdrop in the tank. The compressor and fan are on from the moment it’s plugged in.

 

[Gorgok]

If its on all the time its plugged in i would still think the cooling circuit relay is stuck on. Just hearing the relay click means its trying to do something but it may just be flexing the contact instead of actually moving... I've had my drill press weld on plenty of times, and no amount of flipping the switch will break the contact at that point even if it feels like it should have.

If you can test turning on it to heat, and that works (clicks on, powers the outlet) and stops when you change temp again then the stuck on cooler relay sounds most likely. It would still be cooling, compressor running and fan on as the heater plug turns on, but thats just because the relay is broken.

 

[Airwalk1616]

Regardless of whether he temp of the water is above or below the set temp, the fan and compressor run. But the machine recognizes the temp, starting the 3 min standby mode of either the chilling or heating light blinking until becoming solid at which point the relays kick in. I’ve physically heard the relays click, and also held a multimeter on the ground, which is j9(jumper9) on the board and the red probe to each of the COIL terminals individually. Once the light becomes solid, one of the terminals on one of the relays COIL(opposite relays depending on heating and cooling, the pics show the one closest to the temp sensor connection as heater) voltage goes to zero. I even then bright the set temp up so that it would trigger the heater and IMMEDIATELY, that terminal received power again. Then once the heater light became solid, the same terminal as before, but on the heater relay, lost all voltage. So I assume that means they’re working, right?