Chiller not working

[Keith Winter]

My chiller is behaving oddly. It's only 60 degrees farenheit in the room but it's having trouble chilling the water down to 19 degrees Celsius even with the laser not running for many minutes at a time. It's a CW 6000 model so it's typically a beast, and has no problem chilling the water down to 19 degrees C even in 110 degree weather normally. I've cleaned the filters, checked the water level. What am I missing?

[Merritt Conner]

Your ambient temp is ~16c and I think 20c is the lowest these units are allowed to go. Not sure what type of controller you have so I am just swaging it. My first thought is the system is confused by the low ambient temp, and may not have any issue. Can you bring the ambient room temp up close to 20c? Since everything looks good mechanically, I would look into the controller side. Good luck

[Keith Winter]

My other chiller the same room is working fine, was working fine for 6 months until today. The CW series chillers are adjustable from 15c-30c. It's about 65 degrees in the room right now (18.3 C), and it won't cool down. As soon as I turn on the laser it spikes and cannot keep the water cool.

[Bill George]

Is there warm air blowing out the condenser coil? If not is your compressor running? If nether one I would suspect a control problem. If the compressor is running and no warm air out the condenser, suspect a bad compressor (valves) or a loss of refrigerant.

[Kev Williams]

my guess is your refer unit is toast, and the heat generated by simply running is heating the water. That and the laser of course--

If you can disconnect all the refer workings so only the pump will run, you'll do better. The pump-in-a-bucket may be your best short term option, at least you can add ice cubes--

[Keith Winter]

Ok so I don't know a lot about compressors and such but here goes ;)

On the left side the black thing I'm pointing to that appears to be the compressor yes? It is vibrating so it is running, it is extremely hot, finger burning hot.

The top silver box is moving a small amount of air below it. The fan on the top is running and moving air outside the machine.

Does this tell you guys anything?


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[Ron Gosnell]

Kieth I would take to a local ac shop. Could be low Freon or bad compressor. These don't usually have taps on them to fill and check Freon. The appliance guys have tools that puncture the copper lines and add fittings. They also know about start and run capacitors. They may save you some money in the end.

[Keith Downing]

Kieth I would take to a local ac shop. Could be low Freon or bad compressor. These don't usually have taps on them to fill and check Freon. The appliance guys have tools that puncture the copper lines and add fittings. They also know about start and run capacitors. They may save you some money in the end.

This is good advice. I tend to agree it is probably low Freon or bad compressor. If it's running full time, and all the fans are on, then it's not a controller or sensor issue. Compressors either run and cool or they don't (they never intentionally run and don't cool based on a setting).**

Edit: **I'll add that this is based on my knowledge of commercial food and beer coolers. There may very well be something different with your smaller unit.

[Bill George]

Looks like a small rotary compressor. Is the underneath side of the air cooled condenser coil above clean of dirt and fan running full on? Also the discharge line coming out the the compressor should be hot and it looks like there is a electric solenoid valve Tee'd into it, is that correct? Sometimes on smaller units the compressor will run all the time and when its not calling for cooling they open that valve electrically and bypass hot gas into either the suction line or evaporator. There are better ways for temperature control, but we are looking at a price point.:rolleyes:

PS I still have my gauges and vacuum pump etc, how far are you from Iowa?

[Merritt Conner]

Your thoughts make sense Bill. After some basic online research, I could not tell how these systems control water temp if they get too cold. I have seen a more sophisticated type of digital hot gas bypass controller on SMC and Shinwa units, but there is usually a heater function also built into the systems. I agree with the others, that you can never discount low coolant or a bad compressor, but you would hate to spend that kind of money to find out you had a stuck valve or relay. Something to be said about taping components with a screw driver. :) Looking forward to hearing what the root cause is Keith.

[John Lifer]

I would imagine low freon. Especially if compressor is hot. It is trying to work...
I assume you are pumping water.
And I've got a 5000 and it is set at 19.7C. Room is about 18. Compressor comes on about every 30 minutes for maybe 30 seconds when I'm not running, laser pushes temp up to 20c and compressor will come on till back near 19c.

[Bill George]

I used to work on these systems using hot gas bypass, and if the bypass valve is leaking internally or the coil burnt out they will go into dumping hot gas back into the system. The largest one I ever worked on with that system was over to the Firestone plant here, and it had a 75 Hp refrigeration compressor running a air dryer. Cycling the compressor on and off is a poor way of exact temperature control.

[Keith Winter]

Thanks, great suggestions all around. I think I will see if there is an ac shop I can take it to per Rons suggestion.

[Keith Winter]

Looks like a small rotary compressor. Is the underneath side of the air cooled condenser coil above clean of dirt and fan running full on? Also the discharge line coming out the the compressor should be hot and it looks like there is a electric solenoid valve Tee'd into it, is that correct? Sometimes on smaller units the compressor will run all the time and when its not calling for cooling they open that valve electrically and bypass hot gas into either the suction line or evaporator. There are better ways for temperature control, but we are looking at a price point.:rolleyes:

PS I still have my gauges and vacuum pump etc, how far are you from Iowa?

Thanks Bill long ways away unfortunately in Oklahoma :)

[Keith Winter]

Kieth I would take to a local ac shop. Could be low Freon or bad compressor. These don't usually have taps on them to fill and check Freon. The appliance guys have tools that puncture the copper lines and add fittings. They also know about start and run capacitors. They may save you some money in the end.

Ron what would an ac store be called? Did some googling didn't find much except ac repair technicians like you'd call to your house.

[Bill George]

Ron what would an ac store be called? Did some googling didn't find much except ac repair technicians like you'd call to your house.

The average Joe residential AC guy would not have a clue. You need to find a shop that does commercial refrigeration, and take it in.

Did you check if that bypass valve is dumping hot gas? You can do that by touch, the discharge line comes up and is piped to the inlet of the condenser but there is a Tee fitting with the hot gas solenoid valve on the branch. The discharge line is hot as also the shell of the rotary compressor. If the HG bypass valve is closed for allowing cooling, the line coming out of that valve should be just warm and further away should be cool. If the line is hot all the way of course that means the valve is open for some reason, either by the control system, bad coil or internal leaking. The first two can be fixed, the third requires opening the sealed system and replacing the valve.

[Doug Fisher]

How old is your chiller? If it is a genuine S&A built CW series chiller, most all of those come with a two or three year warranty. S&A does actually provide a bit of customer support when you contact them. Don't let some other AC person do anything to your unit if it is still under warranty.

[Keith Downing]

How old is your chiller? If it is a genuine S&A built CW series chiller, most all of those come with a two or three year warranty. S&A does actually provide a bit of customer support when you contact them. Don't let some other AC person do anything to your unit if it is still under warranty.

I can vouch for this. I emailed them when one of the units I bought was DOA. They helped trouble shoot it and ended up sending me a free replacement pump via 2 day DHL on their dime. And this was a product I had bought second hand, not directly from them. I was very impressed.

[Keith Winter]

Thanks guys, it's about 11 months old.