About four months ago, we replaced our electric water heater. Last weekend the pressure relief valve started dripping small amounts of water intermittently. Some research/analysis resulted in a diagnosis of high pressure due to a one-way valve between us and the street; sure enough, it drips worse when we don't use water for long periods. And it only started recently because we have an Aprilaire humidifier (the kind that has a trickle of fresh water running through it whenever it's running), and of course just turned that off for the spring.
So. The question is: do I *need* an expansion tank? I was given two options:
1) Expansion tank. 2) Just run a tube from the valve to the floor drain nearbyMy concern is whether option (2) -- easy, cheap, etc. -- is a good idea long-term. Will constant slight "blowing" of the valve cause it to fail catastrophically?
I found this on one site: "T&P valves are strictly an emergency measure and should be replaced every 2 years. At 180 psi , the temperature that the T&P valve opens, damage can occur to your system and you may have voided the warranty on your water heater." and: "Plumbing codes require that thermal expansion control be addressed in plumbing systems. A temperature and pressure relief valve is not considered a thermal expansion device. This is because when water is allowed to continuously drip from the T&P relief valve, minerals from the water can build up on the valve, eventually blocking it. This blockage can render the T&P valve useless and potentially lead to hot water heater explosions."
Obviously these concern me! I just don't want to $pend more dollar$ if I don't have to, though it sure sounds like I do have to.
Thanks in advance for any thoughts,
...phsiii