QUESTION: Ed, help! When I open the hot water faucet in my bathroom, the water flows for a little while, then I hear a loud knocking sound in my pipes and then the water stops. If I shut it off and wait a bit it will come back on, but then starts knocking and shutting down all over again. Any ideas? — Brian, Utah

ANSWER: Brian, without checking things out I can't say for sure, but this has all the signs of a loose or broken washer on your hot water shut off valve before the faucet.

What could be happening is, as the hot water passes over or through the broken washer, the washer pieces can actually expand due to the high water temperature. Once the broken washer and/or pieces expand they can actually choke off the pipe and shut down the line. The knocking sound can be the result of the water being shut down in an uneven manner. Usually to repair this problem, the entire house water has to be shut down, then the valve has to be repaired or replaced and any debris need to be flushed from the water lines. If you're not very handy, I'd recommend a licensed plumber for this job.

QUESTION: Ed, I have seen your articles and TV appearances promoting low flush toilets for water conservation. From your professional experience and perhaps from personal travel, have you seen toilets in other parts of the world that are just as good or better for water conservation as the toilets we have available here in the USA?

— Bill, New England

ANSWER: Bill, that is a very "conservative" question! First, I do travel and speak quite a bit about the need to replace the old water guzzling toilets that many homes are still using. A water guzzling toilet is any older style toilet that uses over 1.6 gallons per flush, and believe it or not there are still a load of these old toilets out there!

Many people are reluctant to change because of all the horror stories associated with the first wave of low flush toilets that came out in the early nineties. Now, more then ten years later, new technology and flushing systems have been introduced and I have personally tested and worked with toilets that deliver a "very" powerful flush with only 1.1 gallons of water.

Results like this have convinced me that we need to spread the word about conserving water by changing out all the old 2.5 gallon water guzzler toilets. Getting back to your question, I have not had the pleasure of traveling out of this country yet, but a toilet tour of the world would be a fun trip for a plumber! I have read up on how toilets around the world operate and I'll share some of what I have learned with you.

In America most toilets use a siphon jet system in which water is actually "pulled" from the bowl. In Europe, most toilets are gravity flush, which means the water floods the bowl and is basically pushed out of the bowl. The advantage to a gravity flush is that many of these types of toilets offer full or half flush options, this is why many people perceive overseas toilets to be more efficient.

Because of this, we now have dual flush toilets available here in America. These new toilets use special bowl and tank designs that pull and push the water at the same time, plus gives us the option of a full 1.6 gallon flush or a half flush for smaller jobs.

You might say we were inspired by other countries to be more conservative, but we were able to design a flushing system that does work here in the USA. All Americans should be flush with pride over this accomplishment and should check out the new dual flush toilets!

(Master contractor/plumber Ed Del Grande is nationally knownas the author of the book "Ed Del Grande's House Call" and for hosting TV shows on Scripps Networks and HGTVPro.com. For information visit http://eddelgrande.com or write eddelgrande@hgtvpro.com. Always consult local contractors and codes. Distributed by Scripps Howard News Service, http://www.scrippsnews.net)