My parents have a slab house that is near 65 years old with galvinized plumbing. As might be expected, they are having problems with sediment and scale flaking off the pipes. I recently replaced their worn out dishwasher and discovered scale and sediment completely clogging the intake. Before hooking the new dishwasher up I looked for a water filter to keep this from happening again. I can find a ton of different filters at the big box stores and others but dishwashers work off the hot water line and all the filters I’ve found specify that they are for cold water line use only. I thought about putting in a prehouse filter but even though it would help some I would still have to contend with the junk from the pipes running from that point to the dishwasher outlet. The dishwasher does have a small filter where the hot water flow enters the unit but to get to it to clean it would mean having to pull the dishwasher out each time I wanted to clean it — a real PITA. Other than replacing the plumbing system does anyone have any suggestions or can recommend any suitable filters? Thanks.
Edited 1/17/2008 10:01 am ET by Planman
Replies
I would think that a sight glass type medialess sediment trap wouldn't care if it was hot, but I don't know of any brands.
Assuming you have space in the basement/crawl below, here's what you do:
Get get a large diameter galv nipple (1.5-2") about 6" long, and a matching tee. Screw the nipple into the odd opening of the tee. Use reducers to go from the hot water pipe to the nipple, and more reducers on one end of the tee to feed the DW. Cap the other end of the tee (short nipple and cap).
Orient this device with the 6" long nipple horizontal and the take-off feeding the DW leaving vertically out the top. Insulate after installation, but leave the cap accessible for cleanout.
This setup should allow the larger crud to settle out down the dead end of the tee. Won't do much for the finer stuff, though.
The whole house filter may do more than you think. The real culprit of most of the flakes may be the main water supply. I installed one 6 months ago, it's a pretty big one, and it's pretty full of junk. Right on schedule for it's recommended cartridge replacement. The particles in it look like mostly iron and are coming from the city's lines.