my home has white/blk.water heater has red/blk.what‘s the connection???white to red,blk to blk
Look in your breaker box to verify that the white wire is also going into your breaker and is not grounded in the box. If that's the case somebody decided to save some money on the wire. The white wire may have some black tape around it or was colored black with a marker to show that it's a hot wire. So if the white wire is a hot wire, white to red and black to black to black will be fine.
Where do you try to find it out from?
i dont know alarms thats why i dont try to help
Do you have a third wire? If not then it will not make a difference which wire goes to which. Both will have 120v to them making 240v. There should be a third wire for ground. It will either be a bare wire or have insulation on it. Your house being 30 years old, it should have a ground wire there. I'd do what Ranger recommended about looking at your breaker and see which wire they are your using for the power.
All answers will get the unit to work, however, while Ranger's answer would be a good idea if this was a 120 volt circuit, in the 2 wire with ground, one wire would be hot, (going to the breaker itself in the main box), while the other, usually the white, would be routed to the neutral bar and the bare copper to the ground bar. In a 240 volt unit, both the black and the white wind up being hot, with the bare copper going to the neutral bar. That makes both black and white hot, (both being controlled by it's own breaker). So, in reality, it makes no difference which wire coming from the breaker box you attach to whichever wire from the heater. The unit will still function. Peter's directions will work fine, although not necessarily conforming to the new code. And with all difference to all the professional, licensed, master electricians out there, most folks that perform their own repairs and change out their own water heaters, do their own plumbing, etc., don't particularly care about new or old codes. Their primary consideration at the end of the day is, does it work and work safely. If it does, then we're good, if it doesn't , after several tries, we'll call in someone who really knows what they're doing, like your uncle or your neighbor.
