I had a new gas hot water heater installed about 2 months ago. It was working, getting water hot, etc. A few weeks ago, I had a new furnace/ air conditioning system installed. Now suddenly, water gets lukewarm and stays warm, but will not get hot. Temperature control on unit is set for hottest setting. Checked pilot, power, all the basics, and can find nothing. Any ideas of what I could look for as a cause? -Maya
Check your cold water supply to the hot water heater and feel the pipe is see if it is HOT if it is that means someone put a line to close to the heater and id causing a back flow of cold into hot as this is the way nature designed things HEAT goes to the absence of heat (COLD).
If I am correct send me a private E mail and ILL tell you how to fix this very simply without the use of dangerous check valves.
Wanna bet a cup of coffee it has to do with a lead to the furnace humidifier