Been having problems with this ice machine. Took it into a vacuum (500 microns) and added specified amount of 404A refrigerant. Energized machine and she pulls down to about 60 psi on the low side and about 320 on the high side. It is supposed to run about 20-40 on the low side and 220-280 on the high side. Any suggestions. Dan

You either have a bad compressor due to bad valves or the hot gas harvest valve is leaking. What is the reason you are putting gas in it and how did you charge it, liquid or gas? Give us a lot more detail and it will be easier to tell you what the problem is; the more detail you give us the better we can help you. DrTom4444

Well my other tech was asked too troubleshoot this machine because it was not making ice. He said it was not leaking and that he took it to a vacuum and added specified amount of refrigerant. He could not get it too operate right, so asked if I could check it out. Well I couldn't get it to operate right( suction side 40-20 psi and high pressue side 220-280psi)It was operating @ 320psi and 40-50 psi. I decided to evacuteate system and check for leaks because it was acting like it didn't have enough refrigerant.

Check the hot gas harvest valve by feeling of the line about 12 inches from valve and see if it is hot. If so, replace valve and recharge. DrTom4444

I energized system and waited till 5 minutes into freeze cycle and checked the inlet OF THE HARVEST VALVE AND IT WAS WARM TO THE TOUCH NOT HOT.

The hot gas line has a Tee in it to feed the harvest valve. In the freeze cycle on the evaporator side of the line after the valve far enough away to eliminate heat from conduction it should be cool, not warm. The valve should also be installed with the coil up. Sometimes they are not installed correctly and will be either upside down or on their side. I very much suspect that the valve is leaking which will cause the expansion valve to close and starve the evaporator and raise the temp of the evaporator by raising the pressure. You can pump the freon into the receiver and remove the guts to the valve and replace it. These valves frequently fail on these machines after long use. They leak worse and worse until the evaporator pressure gets too high for it to make ice. If you have to replace the gas make sure to charge liquid only by charging it slowly. If you have charged it by adding the gaseous state you need to vacuum it down after replacing the valve and recharge liquid. This gas is a combination of gases and the machine will never work right charged with gas instead of liquid because the gases have different boiling points and the gas with the lowest boiling point will come out of the tank first. I hope this helps. DrTom4444

Thanks for the information that is very helpful!! I talked to manitowoc customer service and they had me do a couple of tests. With the information that I gave them they said it was probably the compressor. My boss is having me order a new compressor. I got the compressor the other day and I'm in the process replacing the compressor. I have 2 types of brazing material types are HARRIS O PHOS/COPPER BRAZING ALLOW .050X 1/8 and the other is SILVALOY EXCEL 15 .050X 1/8. Which one should I use for this project. Dan

I always use the 15% for almost all welding. If you are welding to the compressor I recommend 49% silver wire and sodium fluoride flux and clean the fitting and tubing well before welding. Many leaks are caused by poor welding practices at the fittings on the compressor. This is because the fittings usually have a thin coating of copper on steel and many times 15% will not stick well like 49%, but the 49% must be heated until it flows well and done quickly so that all flux gets out of joint. DrTom4444

Still having problems with this system!! When we have the ice machine out and away from the wall it makes ice. When we put the system back to where it goes it does not make ice. We put baffles on the machine too divert the condencer fan heat and we have about 82 degree air going into the system when it is in the freeze mold. Does anybody have the same issue and what did you do. Thanks dan

This is a frequent problem with ice machines that are located indoors. Most companies look at it before purchase and buy a split system and mount the condenser on the roof or on the back wall (better). What you need to do is install an exhaust fan directly behind the condenser output and a fresh air intake on the side where air comes into back of unit. About an 18" square fan blowing out and a 12" inlet should work well. DrTom4444

Finally called a service mechanic (Mckinstry) to come in and take a look. What he says is the thickness probe is not working right or it the circuit board!! My question is how do you check to see if thickness probe is good? Again thanks for all your feed back it has been a great help!! Dan

On a Manitowoc you can replace the whole circuit board and sensor with a low pressure switch and a time delay for about $50 or less. There are many problems with the old set up and I usually replace the whole thing with these two components and if the unit is outside with a kit to keep pressure up when harvesting. Basically, you only need to clean the probe to get it to work unless the circuit board is bad. Let me know what you find and I can draw you a diagram to fix it. Write to [email protected]. DrTom4444