Plumbers! I have rust build-up in my hot water line... do I have do a tear out or can I use something else?

Question

I just wanted to know if I could use a solution like CLR or Liquid Scale. I used Liquid Scale once in the lines when I moved into the house, but did not want to overdo it too much and end up eating a hole in the line. This was 9 months ago. Would it be safe to try again? I have very low water pressure on the HOT only and can get some rust sediment to come out when I "bang the pipes" at the main line from the hot water heater, with a rubber mallet. I'm afraid that if I do too much I will just cause a break somewhere in the piping where rust has built up and I will have to repipe it all, which would be costly on a number of levels. I do not have a basement or crawl space, so the pipes are in the walls throughout. Any thoughts? Tips? Help... I need some tricks of the trade.

Follow up details since it seems I won't "fix" it.

It's a small house, slab on grade, with a T at the Hot water Heater... one going about 10 feet to the Kitchen line (sink/dishwasher)... and the other going about 15 total feet to the bathroom (sink/Bathtub)

There is a knock out panel at the bathtub on the opposite side of the wall for access to the piping. What would a replacement job estimate at? Labor cost? Time? Would you guarantee damage done to any kind of laminate flooring, walls or tile?

I am young, and don't want to spend a lot. A small sounding job I know can run big bucks for labor.

Answer 1

I agree with the others, you are fixing to have to replace some pipes. It sounds from your description, that you have galvanized steel pipes. What I do is abandon the old steel pipes in place, and install new CPVC plastic pipes right next to them. You don't have to tear out a lot of drywall, just an 18"X18" hole at the ceiling, and another down where the pipes protrude through the wall. A smaller hole needs to be in the ceiling, so you can glue your pipes from the wall, to the pipes in the ceiling. Plastic pipe is flexible enough to bend it to install it through these holes. It doesn't sound like you have alot of plumbing pipe to replace. It sounds from your description, that you have 1 bath and the kitchen, and maybe a laundry room. Materials would be about $250 for all your pipe and fittings, glue, and insulation. You will need a good drill and drill bit to drill new holes for the pipes to drop out of the ceiling into the walls. Strap the pipes down good, so you won't get "hammering pipes"(vibration), when the water flows through your pipes. Good luck!

Answer 2

The low water pressure suggests that you hot water lines are largely blocked by the rust. You will probably have to replace some or all of the plumbing eventually. Go ahead and try Liquid Scale again, but monitor closely for signs of leaks. It may buy you some time, and the worst case is you'll have to replace the pipes sooner rather than later. Good luck.

Answer 3

I am guessing that you have galvanized steel waterlines. Corrosion will keep building up and the use of chemicals will not do a whole lot. What may happen is the loss of the internal corrosion will allow the outside of the pipe to start leaking. I would start planning on a pipe replacement before it becomes an emergency repair/replacement.