I have had this hot water heater for 4 years (same as age of the house). Recently, this unit has been making a "boiling noise" about 2 times per minute. The sound lasts only a few seconds. The noise happens immediately following hot water use in the house (shower, dishwasher, etc). These noises stop about 5 minutes after they start. The unit is a Bradford White 40 gal heater that uses propane. We have well water. Any ideas on what the problem might be?

I live in a 1990 mobile home, and I lost water pressure for my cold water only. when I took off the faucet screens they were filled with BB sized white chunks. (calcium or lime?) I tried disconnecting the lines and blowing them back with a compressor. being a trailer the lines are only 3/8 in. I thought I had the plastic lines pretty clean and hooked them back up. when I turned the main water back on they pluged up again. There is approx. 40feet of copper line running underground from my well to where it ties into the trailer, which seems to be where all of these deposits are coming from. Is there any way of flushing these deposits out or breaking them up without putting in new pipes? I tried flushing it (with water pressure) between the well and where it hooks up to the trailer, and enough of them deposits to fill a 1 gallon pail came out. but there must still be more, because still no pressure. Is there anything safe to add to the well to disolve these? or is it possible it is coming dirrectly from the well, and new lines would only plug again?