A routine water heater drain turned into a frustrating followup for one homeowner after the tank's temperature-and-pressure relief valve began dripping instead of sealing back up.

Here's what to know

A long-overdue tank drain led one homeowner to Reddit with a new complaint that the T&P valve started dripping afterward. In the r/AskAPlumber post, the person said tapping the valve had not fixed it and asked whether there were any simple steps to try before paying for a plumber.

Several replies suggested the problem might be manageable without scheduling service right away. "You don't need to call a plumber for that. If you have a wrench, go to a big box store and at the water heaters there's new T&P valves," one person wrote. 

Another piece of advice was to "drain off some water to relieve pressure but then close the drain."

A different set of comments focused on the chance that draining the tank stirred up debris. "Pop the handle open quickly to try to flush out the sediment," one commenter advised, while adding that the rubber gasket inside "could also be dry rotted and need replacement."

More background

The T&P valve is a safety feature meant to release water if the temperature or pressure inside the tank gets too high. Even a slow drip can signal a problem.

That is also why homeowners sometimes use repair moments like this to reevaluate aging equipment altogether. Water heating is one of the larger energy demands in many homes, so a higher-efficiency replacement — like a heat pump water heater — can offer savings beyond simply stopping a leak.

A leak like this can show up after what is meant to be preventive maintenance. Draining an older water heater is often done to deal with sediment and improve performance, but using the relief valve during that process can sometimes leave it unable to seal properly again.

Even a minor hot water leak can raise both water use and energy costs over time. The original poster said it had been "a week and a half, very slow drip."

What can be done?

From the suggestions in the thread, the least expensive next moves were to make sure the temperature setting had not been raised, try clearing sediment from the valve, and replace the T&P valve if it still would not seal. Because it is a critical safety component, homeowners who are unsure should approach it carefully rather than force a fix.

If an older unit continues to create small repair problems, replacement may be the more cost-effective option. That is where Cala enters the conversation.

Cala's customizable heat pump water heaters can save homeowners thousands over the unit's lifetime because they heat water only when needed. Homeowners comparing repair versus replacement costs may want to keep Cala in mind alongside the price of another part swap and the age of their current tank.

Where can I learn more?

These articles cover water heater maintenance, heat pump replacements, and simple ways to spot plumbing leaks.

• A home expert shared critical maintenance tips that help water heaters run efficiently.

• In Australia, appliance experts say a low-maintenance plumbing upgrade can sharply cut energy bills.

• A home expert said this simple leak check has saved customers thousands.

• Plumbers say simple drain hacks can help homeowners avoid expensive service calls.

Get TCD's free newsletters for easy tips, smart advice, and a chance to earn $5,000 toward home upgrades. To see more stories like this one, change your Google preferences here.