I am installing nine Honeywell RLV4300 programmable thermostats for my home's 220v baseboard heaters. Of the six installed so far, only two are lighted. The others remain with a blank screen. I have triple checked the wiring and it is correctly and firmly attached with the included wire nuts. I have tried the reset button on the thermostats with no result. I cannot imagine that so many would be defective. I spent an entire day on this and cannot imagine what the problem may be. Can you solve this? Any help will be greatly appreciated.