National 675D coffee machine

[cvending]

Hey everyone. I am a little stumped today.  I have a national 675D FD Coffee vendor. It has been a great working machine. Recently I have developed an issue. The display would read "Cold Water...Try again Later". I ended up replacing the TRIAC at the suggestion of National Vendors. It worked fine for 2 day. Now I am getting a leak from the overflow hose. That filled the wate [ail, shut off the heater. I dumped the bucket, did a fill and it went back to normal. Ovr the weekend, the overflow leask overflowed the bucket but did not shut heater off. Went back this afternoon, hit the F1 button, told me the temp was 181F. I again dumped the bucket and checked the temp and it dropped to 151F. It keeps dropping in temp. The dot is displayed indicating that the heater is heating. Any ideas?

 

Thanks

Steve

[lacanteen]

Not unusual for those heating elements to go bad. I replace the few I have every 2-3 years. The water in the bucket may be from a  valve, especially one not used very much. I now unplug all un-used valves so they don't get fired during a rinse, then eventually cause a leak.

[Walta]

I think you should look at your float. When the floats low water switch is active the board will turn off the heater. If the tank were empty and the heater came on the heater would fail in just a few minutes.

 

The float may have a leak and be full of water or coated in lime so it is heaver and no longer floats. Or the shaft of the float may be limed up and not moving freely.

 

The other thing that can over flow the tank is a leaky inlet valve, leaky in that it will not completely stop the flow of water into the tank. But that would also overflow the waste bucket if you give it enough time.

 

Walta

[rmorris1953]

The temp probe gets corrosion on it and won't give a fast enough temp reading when this happens it overheats till the safety shuts it down. Then it has to cool down enough for it to reset. Durning the overheating the water boils and overflows. Don't think it would be that much but a sticky float could. If I remember correctly the probe goes in at the top so it would make sense to replace both. It has been awhile since I worked on one. If the safety has shut down the heating element the decimal will still flash saying it is heating even when it isn't.  Also, when you lose the heat valves will have tendency to leak.