How to Unclog a Drain Valve

water heater replacement

Sometimes, it’s easy to forget about your home’s water heater. After all, it is usually tucked away sight unseen in a storage closet or out in the garage. But it is a vital part of your home’s plumbing system and – like other appliances – requires maintenance from time to time. In addition to inspecting the water line connections and burner mechanism, the water heater should be drained periodically to avoid the need of water heater replacement.  Armstrong Plumbing, Air & Electric has provided great plumbing service in the Lubbock area since 1934. Give us a call to schedule your water heater inspection and draining.


In the meantime, what happens if you decide to try and drain the water heater yourself and it won’t drain? Well, this is likely due to a clogged drain valve. Clogging may be the result of a buildup of sediment, which is separated from water when your water heater heats it. Over time, depending on how hard the water is in your region, the sediment can clog the drain valve and even cause damage to the tank. We strongly suggest that you give our plumbing pros a call and let them resolve this issue for you, but if you are the DIY type, here’s what you can do to see if your drain valve is clogged:

  1. If your heater is electric, flip off the circuit breaker. If it is gas, turn the on/off knob to off.
  2. Connect a garden hose to the drain valve and open the valve
  3. Open a hot water faucet in your house and leave open; this will counter any negative pressure in the tank.
  4. If water comes out the hose and runs clear, no clogged valve. If it barely trickles or there is no flow at all, your drain valve is clogged.

OK, so what to do now? Again, Armstrong recommends that you call in our licensed plumbers to diagnose and remedy the situation. But there are a few simple things you can try to unclog the valve before calling us:

  • Wait and watch. There’s a chance the clog is minor, and the pressure of the water will force the debris or sediment through the drain line. Give it an hour.
  • Hanger time. Yes, we’re serious … take a stiff wire (such as coat hanger), straighten it out and insert it into the drain valve. Again, if the clog is minor, working the wire around may loosen up the debris/sediment and get the tank draining.

If these simple troubleshooting tips don’t work, the drain valve may be too clogged or deteriorated to salvage. Don’t mess around: give us a call and let the professionals determine if the valve needs to be replaced. Doing so can be a tougher job than you might think.


If the sediment buildup is extreme, it can eventually damage the heater tank and cause it to leak. If this happens, the only option is to replace the water heater. Armstrong Plumbing, Air & Electric’s pros are Lubbock, Texas’s best plumbers and we service all brands and models of water heaters. We also offer a full line of A.O. Smith and Rheem traditional tank heaters and highly rated tankless solutions from Navien. Better Call Armstrong today for all your water heater and plumbing issues!