View Full Version : Redo cold water lines for water softener

06-17-2011, 11:47 AM
I'm in the planning stages of installing a water softener. This post is about the plumbing changes that will be necessary to locate a water softener in the garage. There is no space in the house to put the softener, so the garage is the only option.
The first drawing is the existing cold water plumbing, all located in a crawl space. 3/4" copper line comes in from the street and branches off as noted. The garage floor is about at the same level as the crawlspace ground, about 4 steps down from the house floor level.
I'm proposing in the second drawing cutting into the 3/4 line and running to the water softener (red line) and including two 1/2" tee's to feed the kitchen sink and a rear hose bib. From the water softener, I'll come back in (blue line) and attach to the existing line just ahead of the first 1/2" tee to the 1/2 bath sink.
This will add roughly 100' of 3/4" copper line (ouch $$$) to get to the garage and back.
1) Does this seem like a reasonable plan?
2) Will there be any significant pressure changes caused by the additional piping?
3) I'm also considering adding a sediment filter before the water softener and a charcoal filter after the water softener (insurance agains beads getting into plumbing - it happend to my next door neighbor). Any thoughts or recommendations on this?
4) Any other helpful suggestions?
thanks in advance,


06-17-2011, 12:08 PM
Let's see if these are any easier to read... the first drawing is the proposed changes, and the second drawing is the layout as it is now.

06-18-2011, 04:43 AM
I would leave only connect to the softener what you need. Leave toilets and outdoor Kitchen, hose Bibs on Existing Supply. Use PEX - 1 1/2" PEX is about $500 / 100 ft. and a breeze to install.

Isolate the Softener system with a By-Pass loop and Ball Valves isolation for maintenance.

You do not show a PRV location, but also we do not know the House Pressure front he street and if it is needed.

Just some ideas

06-18-2011, 07:55 AM
You can connect the soft water back into the system ANYWHERE the pipe size is adequate. You DO NOT have to connect at the point where the line was interrupted to go to the softener, unless that is the easiest point to do it. I do not know why anyone would suggest using 1 1/2" PEX in a residence. The pressure changes will be caused by the additional filters you plan to install, especially if they are not maintained properly.

Tom Sawyer
06-18-2011, 09:54 AM
Most softeners come with a bypass built in so adding a bunch of ball valves is a waste of time and money. Do not leave the toilets off the softener, your fill valves will last longer. The only thing I bypass typically is the sillcocks. Unless you have a 15 bath mansion, 1-1/2" is way way larger than a residence needs.

06-19-2011, 03:46 PM
This is what I did on mine:


The blue shut off valve on the left is the main water line feed coming into the garage from under the house off the pressure regulator. I highly recommend adding a shut off valve for easier access in an emergency (mine was under the house), plus it makes changing the filter easier. Our city water tap is at the end of the main on our street, so we get a lot of crud as you can tell by the filter condition. I have since replaced the filter housing to a different model after this one basically fell apart.

The water softener is to the right of the filter and from there it feeds to the water heater out of view on the left and the cold water supply going back under the house.

I recommend connecting the 3/4" feed line off your water softener to a 3/4" cold water supply line feeding the rest of the house and not to a 1/2" line as this could affect your water pressure. I only notice a decrease in water pressure when the filter needs to be changed. And yes, the water softener does have bypass valves.

06-20-2011, 07:30 AM
Thanks for all the helpful replies. I will be keeping all the new plumbing lines 3/4 copper despite the cost just to keep things consistent. I'm not sure, but the electrical ground may be connected to the copper somewhere and I don't want to interrupt that with pex.
HJ - thanks for the info regarding the filters potentially causing the pressure drop.
I'm going to go ahead with a bypass using ball valves as a backup to the bypass valve on the water softener. Some good insurance there in my mind.
Filter questions:
- I read somewhere that it was recommended placing pressure guages before and after the filters so that when there is too much pressure drop between the 'before filter' and 'after filter', then that's a good indicaiton that it's time to change the filter.
Is this a good idea? I'm concerned about the potential for leaks since I've never plumbed a pressure guage into water lines before. If I just set up a quarterly or semi-annual reminder in my calendar to change the filters (unless I noticed a pressure drop in the house sooner), would that be okay?
I'll have questions about adding a new drain for the softener, but I'll post a new entry for that after I do some more research.
thanks all!

06-20-2011, 09:14 AM
You didn't specify if you're on city water or a well unless I've overlooked it. Adding pressure gauges is fine however I really don't think that is necessary because water pressure normally fluctuates during the day which may provide a false gauge indicator of the filter cartridge condition. Make sure you buy a good quality pressure gauge designed for permanent full time use if you decide to add one, but really if your filter has a see through housing like mine, then that will provide a good visual indicator of the filter cartridge condition. I change mine every 3-6 months depending on how the filter cartridge looks as water usage will very from month to month.

If you put a single water shutoff valve on the main line coming in as I did, then adding the extra bypass valves is not necessary as they serve no real purpose. As a person who also tends to over analyze things myself, honestly I think you're going to a lot of extra trouble adding the gauges and extra bypass valves for no benefit in return as any water pressure drop should not be significant enough to cause concern or problems in most cases. The extra gauges/valves would not resolve that issue even if it did exist.