EZ9 sterilizer "low Water"

There is a water level sensor inside the reservoir. It can sometimes get stuck. Try working it up and down a bit and see if the error goes away.

Hi-- if the unit is displaying "Low water" on the LCD display and is failing cycles it is because the chamber is loosing water during the cycle. This has nothing to do with the float switch! The first thing to check would be the 3mm exhaust valve. Chances are it has debris in it or needs to be replaced. I have been working on these units since 1992. Please feel free to contact me with any further questions. Regards, Kevin Bresnahan BaySide Technical Services Worcester, MA 01606 508-735-4817 sales@mytuttnauer.com

[quote=cbetdon1]unit display says low water all the time. It is also failing the cycle. Would this be the chamber sensor or the resovoir sensor? Any ideas? Thanks!![/quote] Don- I repair the autoclaves in Worcester, MA for your brothers at Aramark (Fallon Clinic/Worc. Med City) Just did a job for Jay Anderson Hi-- if the unit is displaying "Low water" on the LCD display and is failing cycles it is because the chamber is loosing water during the cycle. This has nothing to do with the float switch! The first thing to check would be the 3mm exhaust valve. Chances are it has debris in it or needs to be replaced. I have been working on these units since 1992. Please feel free to contact me with any further questions. Regards, Kevin Bresnahan BaySide Technical Services Worcester, MA 01606 508-735-4817 www.sales@mytuttnauer.com

The problem most likely is the sensor in the chamber, while running the cycle if there are no problems with pressure build up then i would say you are not loosing water and the sensor is going bad on you. Try cleaning the sensor by running a cycle with chamber brite and if that does not work replace sensor. Please contact me if you will need further help- Best Regards, Greg Rainey Technical Engineer Service@heidolph.com Heidolph USA (Main Office) Elk Grove Village, IL 60007 Office: 224-265-9600 Ext: 116

"Low Water" displayed on the LCD screen refers to the water level in the chamber only. If you get a proper fill of 30- 35 seconds then you should be able to run a full cycle. If the error code pops up while the unit is building pressure chances are it's the valve. Chances are if the water sensing electrode in the chamber is bad then the pump will keep starting and stoping while trying to satisfy the sensor thus filling the chamber with too much water and you would not be able to start a cycle. If the unit displays the error code even while not running a cycle then you have to check the sensor and trace it back to a board. (To check the sensor without a test point board- disconnect the green wire from the bottom of the sensor and take an OHM's reading from the tab to the chassis. It should show and open line. If you have any continuity you should replace the sensor. You can then power some water into the chamber and when te tip of the sensor is under water you shold have continuity.) You can reset the unit back to factory defaults by turning "off" the power and then turning the power back "On" while depressing the "STOP" button. This will clean any rouge code that may have corrupted your unit maybe due to a power fluctuation. The "Low Water" code is the most mis diagnosed code on this machine. 99% of the time I find it is an issue with the 3mm exhaust valve. This is the valve that connects to the condensing coil in the water reservoir. If the seat in the valve does not hold under the chambers pressure the water will pass through it traveling thru the condensing coil and out into the water reservoir. The "low Water" error code is then displayed as the chamber runs low on water causing the tip of the sensor to go dry. This is one of the "fail safes" built into the unit to prevent running the chamber dry and causing a lot of damage to the unit.

This was the point I was making, if you don't see water going back into the reservoir during the cycle build up and there is no problem with the buildup of temperature or pressure most likely the problem is the sensor. The water sensing Electrode tends to throw users for a loop in most cases, sometimes working then not. If you were really having a problem with the valve then you would see the water lost as unit builds pressure this I have seen with my own eyes. Pulling the sensor out and just checking its condition can make it more obvious if you see that its discolored from its normal state, usually you can see a greenish blue discoloration within the stem. I have remove all water from an autoclave while doing an error code test and cause the low water error code and it took the unit about 45mins to see there was no water in chamber, when the sensor goes bad you start to see the error code appear more rapidly and not always consistently.

One other consideration...it is possible to loose steam thru the door if it is not closed tight enough, assuming a good gasket. The end user typically has this problem when the door closing mechanism has inadequate maintenance/lubrication: they are used to closing it "tight" by feel, when the closing device binds up and the turns against the door fork, the excess friction makes the door "feel" tight. If you look at the clearance between the door fork and the chamber frame and minimize it you should get a good seal. If the door isn't tight enough, it acts as a pressure relief and allows steam to slowly (and almost imperceptably) leak out when the pressure inside the chamber approaches the tension of the door. Once the chamber is dry, the unit overheats triggering a "low water" message. I have also seen excessive blow by of worn air jet allow a higher than normal passage of steam and subsequent loss of chamber water. Finally, if there is any other steam leak in the reservoir, it can be masked by the normal functions of the air jet. I have a tool which fits over the air jet and re-routes the output away from the reservoir so that I can check for other source of (unwanted) steam.

I believe that any time one sees a "low water" message that you should start with the 3mm exhaust valve. I physically remove the valve and inspect it. The 10 minutes it takes to pull this valve out and give it the once over can save hours of time trouble shooting everything else. The seats on these valves are wear items and they need to be replaced every now and then (2700 cycles). By starting here you are working your way out of the chamber and verifying everything else on the way to the front of the unit. I have been working on these machines since 1992. It amazes me how many techs over look the 3mm exhaust valve and dismiss it. In the past, I have been to offices that have had one, two and three other techs/ companies looked at a machine with a "low water" error and not be able to correctly repair the machine. If you guys want to see some pics of what a bad valve looks like contact me and I'll e-mail some pictures. Kevin BaySide Technical Services 508-735-4817

Brings up a good point. Went back to recheck unit and really talked to operator. The door gasket seems bad (losing steam) and the water pump is really loud (going bad?). The pressure seems to build up ok and water level looks good but with allot of bubbles in it. Cleaned chamber water sensor. Im thinking new door gasket and check water pump for leaks. Does this soud right. I am going this afternoon to watch a complete cycle. Haven't had time to really look at it until today. Exhaust seems ok.Ideas????

The water pump could sound loud because it is not mounted properly or you are hearing the inline filter hitting on something. A bad door gasket could contribute to a "low water" error. However, you should always be looking for multiple issues. For example, you state there are a lot of bubbles in the water reservoir. Where do you think they are coming from? I bet the chamber ! So, how do the bubbles get from the chamber back into the water reservoir ? Through the 3mm exhaust valve !!! Give me a call if you would like. Kevin BaySide Technical Services 508-735-4817 Authourized Tuttnauer Sales & Service