Outside temp not measuring correctly

hello
u'd need a proper manual for this in my opinion
like there are plenty of dealers and online shops that deal in those..
you can get some free at reliable-store and it;s actually really illustrative

This is for a DWS-150B it may be similar or at least give you an idea
DWS 150 IB Weather Watcher

Usually it is due to bad batteries or remote is too far away from home unit. Put units next to each other and press the channel button on front of the home unit. It will start a search to find the remote. If it finds it with a temp reading press the channel button again and you should hear a beep. Channel is locked in. If you still do not get a temp reading try changing batteries in both units and try again. Another try is to unplug the home unit and wait several minutes with no batteries in either house unit or remote. Replace batteries in remote then in house unit and plug back into power. Set all settings and see if you get the reading. If not try step one again. Weak batteries will do the same thing as well as remote to far away from unit.

http://www.manualnguide.com/shared/dws-150-ibweatherwatcher/11/

How do I get my envirostation 400 to stop beeping or stop changing the channel

You may download a copy of the manual here.

the above response is wrong. that is not the manual for envirastation dws-130

You must remove the batteries in the base unit, replace them, and it should work properly. You can press the Tx button on the back of the remote unit to verify the RF reception. To ensure it is working properly, place both units next to each other indoors and make sure they read the same temperature.
The manual can be found here. Refer to page 3 for more information.

The 126 is not an error code, but it maybe the temp of the water that the heater is reading. If the heater thinks the water is 126 degrees, it will not start at all.

If the heater is reading the wrong water temp, the problem is the Thermister, which is the sensor that is suppose to read the water temp. You will need to replace this sensor in order to correct the problem with the heater. It is really easy to do!

If you have a manual for the heater, if you go to the Replacement Parts Listing for the Electrical System, page 53 in the online version, the Thermistor is Item #9. It goes into the left side of the manifold in the to place, between the first two manifold bolts.