i think kuyato hit it right on the head! i'm running a rke. having been a marine engineer for sea-land, one of the frist things i noticed about this unit is that NOTHING is sealed. nothing! not only this but for communactions we used (they say high grade) i say home depot low voltage telephone cables and jacks. this in itself is not a problem, its when the salt air from our tanks hits these connections we have problems. the smallest amount of corrosion on these connectors causes huge grounding problems and as a result loss communications to the modules. there are ways to combat this. in my case instead of mounting anything under my stand i built a add-on box to mount the controller and modules in to limit the amount of moisture that attacks the system. i extended some of my cables and ran them thru weather pack box connectors. i used liquid electric tap on all connectors, this does a good job of sealing the connection and is easily removed if needed. the drier you keep your system, no matter who builds it, the better it will preform. and always always always have back-ups, we all had spare timers at some point! :}