I have a new 40 gal. "Gas" H/W heater installed about 4 weeks ago by a professional. It worked fine up until about a week ago, then the pilot began going out and would not re-ignite until I disconnected the 2 leads which I assume are connected to the piazo/thermocouple. Once I did that, then re-connected them after about 5 min. it would reignite using the regular mfg. Defined process, but only for a short time. I had the company send me out a new gas valve, (which I installed myself), and it lit just fine on the first try... now it's doing the same thing! The vent is T'd into the furnace flu at a distance of about40" from the heat exchanger, so I don't think there is a draft problem. Any ideas?