My AquaHot unit will not work. In the bay, above the Aquahot 250D the network card has no light showing. It is usually green. It appears to have no connection or power. The 250D will not work on diesel or electric. I have checked the breakers under the master bath lavatory. I have checked all of the 5 amp fuses on the network card. All breakers appear to be set correctly. Any ideas?