Davis Vantage Pro2 Rain Gauge Problems

This afternoon, it was raining very hard when I noticed that my Davis showed 4.12" of rain. I was surprised, then looked at the my $5 backup rain gauge and it read about 2". So I knew something was wrong. The rain continued but the Davis 4.12" remained, never increasing. What could be the problem? I’m sure someone has had this problem. I have looked on this forum and saw some info but want fresh suggestions, if possible. Is there anything I can do to fix this?

Apparently, all the functions associated with the outdoor data collector have stopped. Not sure what to do now.

Any suggestions from anyone? To see my weather station data, got to https://www.wunderground.com/personal-weather-station/dashboard?ID=KALPRATT3#history

possible blockage of the funnel, or a very strong spiders web :smiley: or the reed switch as given up…

I would suggest that your ISS has given up? Do the internal measurements change e.g. Pressure?

Paul

If it’s a wireless VP2 then start by changing the battery in the ISS and then check that the ISS is transmitting by flicking switch #4 into test mode. You should see a green LED flashing under the battery casing, if not then the ISS isn’t sending anything to the console.
If the ISS is transmitting then you should see the ISS station number on the console, at the bottom of the screen, usually #1. If not put the console into setup mode and see if it’s receiving data from any station.

I checked the battery - it is 100%. Put into test mode and the green LED flashed. The indoor console shows station # 5, so does that mean it is receiving? The temperature here is stable since it is cloudy so don’t know if the temperature is being updated.

The sun finally came out and the temperature rose a half degree, so maybe it is working ok now. I dried out the compartment where the transmitter and switches are. Maybe that helped or the ISS dried out with the sun.

Thanks, Budgie. You always have good advice.

Will give an update in an hour or two and see if the ISS is working ok.

LATEST UPDATE: The ISS seems to be transmitting all its data, so for now, all is ok.


I would say it was probably the rain gauge components that maybe got affected by the rain as the graph in your attachment shows it was torrential. The graph also shows that while the rain data had stopped updating, the temperature/humidity and wind speed/direction were still updating so the ISS was transmitting ok.
You haven’t had rain since to test the rain gauge is ok now? Maybe test by pouring some water in and see if it registers?

Just put some water in the rain gauge to get 2 flips. It shows 0.02" on my console. So I guess the rain gauge works ok.

You are correct in saying the rain was torrential. I don’t believe I’ve ever seen such a heavy downpour. Not sure why it recorded 4.21" since a backup tube gauge showed about 2.4". Would such a rain cause the rain total to be so high?

It was probably recording ok until a certain point when water got into the reed switch area causing abnormal interference thus high readings and eventually cutting out. Did WD set an all time record rain rate?

It sure did! Over 4 inches an hour.

The rain gauge is acting up again. We have had no rain this afternoon, but the ISS has recorded 0.79". About 0.02" of that was when I tested whether the gauge was recording. I have no idea what might be wrong now. I just now unplugged the rain connection in the ISS. Guess that will stop incorrect recorded rain, but also won’t record any real rain. Any suggestions on what I might do now?

check maybe for a spider web , holding the tipping bucket up a bit
or it could be hair line crack in the reed switch (Davis should really change to using a hall effect sensor like they have done for the anenometer)

Checked everything around the bucket and found nothing. This weather station was bought in 2008. Could it just be at the end of its lifespan?

Check the ISS for water leak the gasket does not seal on older units and water runs on the back of the circuit board and will short out giving a rain count.

That may be the problem as I found some water inside the “sealed” ISS. I dried it out but the damage may have already been done. The other data seems to not have been affected, only the rain count. Guess I need to get a new system. Sound right?

Check the back side of the printed circuit board for corrosion on the traces.

Several months ago, I replaced the tipping buckets with a new tipping spoon assembly. It helped the accuracy a great deal.

Today we had a brief shower, probably 0.1 in, but the rain total went crazy. Fourth day in a row with rain and readings accurate. Kept climbing till it showed over 6 inches. First thought was the new tipping spoon had gone south, so I put the old bucket assembly back in. Nope, still accumulating rain, though the sun was out by then. Checked where the rain sensor plugs into the ISS, all dry. Stuck the new tipping spoon back in.

Decided to reset everything, console and ISS. Pulled power and batteries on console, pulled solar panel and battery on ISS. Took the opportunity to replace the ISS battery.

So far that seems to have corrected the problem. I bought this unit in 2007, had very few issues. Replaced the ISS temp/humidity (humidity reading erratic) sensor, anemometer assembly (bearings were going), and recently the rain sensor assembly.

Update to post above.

After a lot of rain when tropical depression Fred dumped 7" of rain on us in two days, my VP2 went wild with the rain again. I took the circuit board out of the ISS to clean and check for any corrosion, etc. on the back of the board, per zepplines suggestion. There was none, and the circuit card appears it is sealed with a coating so moisture cannot get to the board. The inside of the ISS was also completely dry after 2 days of heavy rain.

I still cleaned the circuit card with alcohol, and re-assembled. Rain continued to register even with the sun out, so I disconnected the tipping spoon and ordered a new ISS circuit card, Also got a new cover/solar cell at the same time.

The new ISS is producing much better accuracy for rain, as it got tested when the remnants of hurricane Ian came through, but without the volume of rain Fred dumped. I had been using the rain offset feature of WD to for underreporting rainfall as compared to a manual rain gauge located withing a couple of feed of the Davis ISS.