Edwin,


If it is solar, could just be cloudy days. If it is electric, one of the
elements may be burned out.

Yeah, I was going to say that about the solar heater. We from the
plumbing newsgroup run into that question all the time. Matter of fact,
the local supply house is running a two for one solar water heater sale.
You'd be surprized how many plumbers haven't been certified in Solar
Water Heater repair. It's scandalous.