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Tanklets > Backflushing Blocked Piping

Q: We had poor to little water pressure in the upstairs bathroom (hot water only). I thought the old galvanized lines were closing up. So, I had all the water lines from the feed coming into the house replaced(hot and cold). After doing that the hot water pressure was still bad. Maybe a little worse. So, we thought maybe it's the gas hot water heater. Check to make sure the hot water pipe coming out of the heater was plugged. It is not! Drained the tank and let fresh water run through hose. Seemed like there was good pressure. We're stumped!!!! Any answers?

A: Hello: You need to get a pressure gauge. Used correctly, it will point you to the problem/s. First, what is static pressure; that is, with no water flowing? Measure static where water comes into the house and also with a couple of taps running. If it is not much different either way, you know the main line to the house is good. If it drops off a lot, you know the main is clogged up somewhat.

Put the gauge on the drain valve of the water heater. Test again. This tells you about the pipes to the heater. Adapt a fitting, say the showerhead arm, to accept your gauge. Now run hot water elsewhere and see what you get. This process narrows down the potential problem so you can know where to look. Look into "backflushing" mentioned in "Tanklets." Some of the work done could have sent chunks of rust further up the lines -- Larry ( 2/5/09)

Q: My girlfriend's mom lives in trailer park. They have cold water, but they say that there's no hot water at all, meaning hot water trickles out very very slowly. Is there a clog and do I need to get a new tank? Thank you

A: Four possibilities. No. 1 -- The cold-water shutoff has failed somehow and the water heater has no pressure going to it. You can check that by opening the water heater drain valve or temperature/pressure relief valve. If there is good pressure there, then that is not the problem. No. 2 -- The faucet aerator is clogged with gunk. Take it off and check it. If it is clean, then.... No. 3 -- The plumbing between the faucet and the water heater is clogged. Go to Tanklets and read the one on backflushing to check that. No. 4 -- There is blockage at the tank, perhaps a malfunctioning heat-trap nipple. You'll need to disconnect the hot-side plumbing to check for that. -- Randy ( 4/25/08)

Q: We just installed a 65 gal water heater in the house and everything appears to be working. All but one faucet seem to have similar water pressure as before. However, the sink in the kitchen has no water pressure at all. We've beat (softly) on the pipes, tried all variations of faucets on and off, but nothing has helped. What could be wrong, and how do we fix this?

A: Should I assume you still have cold water at the faucet but no hot? If so, there is a neat trick. You can backflush the hot side plumbing to rinse out the sediment that likely is blocking the tap.

Start by blocking off the areator. Do this by cutting some heavy tape in a small circle that just fits inside the aerator. Screw the aerator back on. Shut off the gas (or power) and then water to your new heater. Attach a hose and then open the drain valve. Go back to the plugged faucet and open both hot and cold, or put it in the center position if it's a single lever type. What will happen is cold water will not be able to go out the spout so will try to go back along the hot pipe back to the water heater. As the drain is open and water off, there is no pressure there.

The little bit of sediment will wind up in the bottom of the heater harmlessly. Once things start to flow, let it run for a few minutes to be sure the sediment is out of the pipes. If there is a spray unit, it could very well be clogged up and need to be taken apart to clean. Next time you replace the heater, be sure to open up the tub spout first and let it run 'till clear. That will usually get any debris in the line, out. -- Larry (1/29/05)