Question - We recently had a lavatory installed in our basement. Because the sewer pipe is overhead, we had to install a sewage ejector pump. We now have a problem whenever the pump goes off. There is a rather loud bang at the end of the ejection process.
We have had two plumbers look at the problem, and neither seems to know the cause. Also, we had the floor of the garage dug up, and the sewer pipe straightened since we believed that was the cause. We still have the banging noise. Do you have any advice?
Answer - This is a fairly common problem with sewage ejector pumps. The noise is caused by the closing of the check valve.
A check valve is one that allows flow in only one direction. It is used with ejector systems to prevent backflow of sewage into the basin after each pumping cycle. This extends the pump's life by preventing it from cycling too frequently.
You will not be able to eliminate the noise completely, but you can reduce it. Where local plumbing codes permit, you can install a section of flexible hose in the piping as a vibration and sound isolator. To further reduce the noise transmission, try wrapping a rubberized material around the section of the pipe under the hold-down clamps.
Finally, the valve's installation effects the amount of noise. Some pump companies recommend that the valve be installed in a horizontal position with the hinge facing up. This will prevent solids from lodging on top of the flapper, preventing it from opening again on start-up.
Question - I installed a circulating pump in my hot-water system as described in the September '94 Homeowners Clinic. Now the hot water is rusty. I have a timer on it so when we first turn on the hot water, it's very rusty. It never completely clears up.
Before installing this circulation pump, I cleaned and flushed out the water heater, which is 1 year old. How do I get rid of the rust without having to buy a new water heater?
Answer - There are two possible sources for the rust. The tank itself is usually not one of them. Most of today's water heaters have a high quality glass lining, and it's very rare to have a lining failure significant enough to cause rusty water.
The rusty water is either caused by the circulator pump or iron-reducing bacteria. If the pump has a cast-iron housing, rather than a brass or bronze housing, this could be the problem. If the problem is not caused by the pump, then I would suspect iron-reducing bacteria.
Unlike other kinds of water-borne bacteria, this kind is not harmful. It is common in water-distribution piping in which soluble iron exceeds .2 parts per million. Soluble iron in the water provides food for the bacteria, and the rusty discolored water is the end result of the bacteria-feeding process.
The pump is probably stirring up the bacteria's waste products, which accumulate at the bottom of the hot-water tank. Correcting the problem will require chlorinating the water heater and all of the hot-water system piping. If the water heater has a severe iron bacteria infestation, more than one treatment may be required.