Water around the base of your hot water tank is one of those problems that does not improve on its own. The question is whether you need a $150 repair or a $1,500 replacement. Here is how to tell.
Where is the water coming from?
The location of the leak tells you most of what you need to know.
Water from the discharge pipe (TPR valve)
The temperature pressure relief valve is on the side of the tank. Small slow drips from the discharge pipe below it are normal and expected. Heavy continuous flow means the valve has failed and is letting water through constantly. Repair: replace the valve. Cost $150 to $250.
Water from a connection or fitting
The connections at the top of the tank (inlet, outlet, gas connection if applicable) can develop drips over years. Usually a tightening or a new seal fixes it. Repair: tighten or replace the fitting. Cost $80 to $200.
Water from the bottom of the tank itself
This is the bad one. Water pooling around the base of the tank with no visible source, particularly if it is rusty or discoloured, usually means the tank has corroded through internally. Replace. There is no economic repair for a corroded tank.
Water from the heating element area
For electric tanks, the element seal can fail and water leaks from there. For gas tanks, the gas valve can develop leaks. Both are usually repairable but it depends on the tank's age.
Age matters
If your tank is under 8 years old, repair almost always makes sense. The body of the tank still has years of service left.
If your tank is 10 to 12 years old, repair vs replace is roughly equal cost over the next 5 years. Depends on what is leaking and how the rest of the tank looks.
If your tank is 12+ years old and showing rust at the base, replace. The next failure is months away regardless of what you fix now.
The 'fix the symptom and hope' trap
People sometimes fix the visible leak (a TPR valve, a fitting) when the underlying problem is that the tank is at end of life. The replacement valve fails again in 6 months. The fittings keep weeping. False economy.
Get a plumber to assess
If you are unsure, a plumber can inspect and tell you honestly whether to repair or replace. We do this assessment free as part of a quote. We will tell you to repair if that is the right call, even though it is a smaller job.