Baseline troubleshooting

Hello,

we are currently using skalar at a remote location, and about two days ago, we are having trouble with the baseline. TCN always stay about 1.2-1.3 and WAD 1.6-1.7. But now TCN is sitting at 2and WAD is at 3. The baseline is also unstable, with blip like picks all over, thats before using any in house prep solutions. only using DI water. what will be the possible issue here?, we are pretty sure that all solutions lines are flowing well and the glass coils are also clean. We have limited information on possible issues to encounter with the instrument. Can you please help us trouble shoot any possible cause that can affect the baseline and the instrument performance.