I've got a 50 gallon low-boy that has been leaking for about 3 years. It's a Bradford-White or AO Sloan, not sure which. I never exactly knew where because it was so slow but in the past 6 months it got to the point where I could see an occasional drip from the temp & pressure valve drain pipe. I put a bucket there and it fills up with about 8 oz. of water in three weeks; it's enough to keep that area of the crawl space moist and moldy.
As an experiment I adjusted the water pressure regulator valve by turning it three turns CCW. The valve has a plastic collar on the adjustment nut to keep it set at a preset point (see the attached pic). The valve body reads, "5 - 65 PSI" so I presume the setting is something like 45 because the water flow before adjusting was actually kind of weak; now, it's so weak the shower thing won't engage unless I hold it for a long time. Anyway, I turned down the pressure, set the bucket and a month later no water coming from the T&P valve.
My water heater was repaired (if you can call it that) in 2008, which was near the end of its warranty period but still within it. Long story short, only parts were covered under the warranty ($29) but the labour was not ($135). I bring this up only because this incredibly slow drip coincidentally started about the same time my hero showed up and performed his 8 minute miracle repair.
I've read from the experienced users that 80 psi is the max a household should have -- I am quite certain I am well below that. To give you an even better idea how low it already is, when I hook up one of those oscillating sprinklers it sticks in one position because there ain't enough pressure to keep it moving.
So, that leaves temperature. I have never adjusted the thermostat on the low boy but I did check out the setting once repairs were made and it was and still is set to the exact middle of the dial. I don't know the exact water temp coming out but if you turn on the hot tap all the way you can keep your hand there and it won't get burned (but it is warm enough).
Appreciate any comments.