Alrighty......
When you state " water heater not turning off and releases the pressure relief valve" do mean the relief valve is popping open and BLOWING
OR do you mean the relief valve is 'weeping'
BLOWING....
That is a failure of the T-stat AND the ECO
T-stat is the normal temp controlling the heat cycles. OPENS when water temp reaches 140*F and CLOSES when water temp drops to >110*F
Then the ECO has to fail to OPEN. It is the 'Energy Cut Off' (High temp t-stat)
It OPENS when water temp reaches 180*F and shuts down all heating functions. When it OPENS it triggers the 'RED Fault Light' on the ON/OFF switch and 'LOCKS OUT' the water heater controls so heating can not occur.
ECO resets when temp drops >150*F BUT 'RED FAULT'/'LOCK OUT' has to be manually reset by turning switch OFF, wait 30 seconds then turn back ON
T&P Relief Valve is last ditch safety device.
POPS OPEN when temp reaches 210*F OR pressure increases to 150PSI
T-stat/ECO need to be replaced.....tank area where t-stats touch wall of tank should be clean and then both t-stats need to be held TIGHTLY against tank wall
Weeping..........
That is easier. Means 'air pocket' in top of tank has been lost so pressure inside tank increases when water is being heated
Water swells when heated and does not compress so pressure will increase causing T&P Relief Valve to weep (drip water continuously)
Air Pocket in top of tank allows for swelling of hot water and control of pressure increase
To re-establish air pocket
Turn water supply OFF
Open a faucet hotside to relieve any pressure---leave open
OPEN T&P Relief Valve..hold open until water stops running out (CAUTION: WATER CAN BE SCALDING HOT!!!!)
Let T&P Snap closed
Close open faucet
Turn water supply back on
