How to Put a Water Softener in Bypass — and When You Should

How do I put my water softener in bypass?

Find the bypass and put it in its bypass position: either the valve built onto the back of the softener’s control head, or a set of three valves on the pipes beside it. Pentair’s manual for the Fleck 5600SXT covers both kinds in one step: if the softener has an integral bypass valve, put it in the Bypass position; if it has a three-valve bypass, first open the valve in the bypass line, then close the valves at the inlet and outlet [1].

The makers insist a bypass is there. Pentair says to always provide for one if the unit does not come with one [1]; EcoWater says to always install its bypass valve or a three-valve bypass system, because bypass valves let you turn off water to the softener for repairs while the house pipes still have water [3].

The drawing below shows the three-valve kind in both positions. The built-on kind does the same job inside one body: it closes the softener off and joins the inlet straight to the outlet.

Which way is bypass on the valve on the back of my softener?

It depends on the make, so read the marks on the valve and its manual before you move anything. Two common designs work like this.

Push-pull stem. On EcoWater’s single bypass valve, the stem is pulled out for service (soft water) and pushed in for bypass [3].

Two red handles. Clack’s WS1 bypass is two plug valves, each turned by a red arrow-shaped handle that shows which way the water goes. In normal operation both handles point the way of the flow arrows engraved on the control valve; in bypass both point to the centre of the bypass, the control valve is isolated from the water pressure, and untreated water goes to the house [2].

That Clack bypass has two more positions, and one of them matters. With the inlet handle pointing to the centre and the outlet handle pointing with the flow, it is in shut-off: the water is shut off to the plumbing system [2]. If the house goes dry after you touch the bypass, check that both handles point to the centre. The fourth position, diagnostic, is for a service technician working on the valve under pressure [2].

How do I bypass a softener that has three valves?

Open the middle valve first, then close the other two. The Fleck manual gives that order for a three-valve bypass: open the valve in the bypass line, then close the valves at the softener’s inlet and outlet [1]. EcoWater’s installation drawing labels the same three positions: for soft-water service, the inlet and outlet valves open; for hard-water bypass, inlet and outlet closed and the bypass valve open [3].

Which valve is which? The inlet valve is on the pipe coming from the meter into the softener, the outlet valve is on the pipe from the softener to the house, and the bypass valve is on the short pipe that joins the two without passing through the softener. Opening the bypass valve first means the house is never cut off while you turn the other two.

Most of these are quarter-turn ball valves. As a general trade convention, a lever in line with the pipe is open and a lever across the pipe is closed; turn each one fully, not part way.

On an outdoor softener like the one in these photographs, the valves are on the pipes beside the tanks, out in the weather. Before you need them, find which valve is which and make sure each handle turns. Why the loop is there in the first place is covered in our article on installing a softener outside.

How do I put my water softener back in service?

Slowly. Both manuals we read say so. The Fleck manual’s start-up step is to place the bypass in the service position slowly and let water flow into the mineral tank, then slowly open a nearby cold tap and let it run until the air is out of the lines [1]. EcoWater’s manual gives the reason — to prevent excessive air pressure in the softener and the plumbing — and the order [3]:

Built-on bypass: move the valve stem slowly towards service, pausing several times so the unit pressurizes slowly [3].

Three valves: fully close the bypass valve and open the outlet valve, then open the inlet valve slowly, pausing several times [3].

Then run a cold tap until the water comes steady, with no spitting; some air in the lines is expected after this [1]. The Fleck manual adds a note after every repair: be sure to shut off any bypass line [1]. A middle valve left open sends hard water past the softener, and the Fleck troubleshooting table lists an open bypass valve as a cause of hard water, with the fix: close it [1].

When should I put my water softener in bypass?

Whenever the softener has to be isolated, or the water you are about to use does not need softening.

A leak at the softener, or a repair. This is what the bypass is for. Clack says the bypass is typically used to isolate the control valve from the plumbing system’s water pressure for repairs or maintenance [2], and the Fleck service instructions start every repair by putting the softener in bypass and relieving the pressure inside it [1]. Pentair warns that the system must be depressurized before any connection is removed [1]. If the leak is on the pipe before the bypass, or the bypass itself, the bypass cannot stop it — close the main shutoff.

Filling a pool or a long run on a hose. EcoWater recommends that outside faucets stay on hard water to conserve salt and softening capacity [3]. Water sent through the softener to fill a pool uses up softening capacity the softener then has to regenerate. If your hose bibs already come off the pipe before the softener, they are on hard water anyway and there is nothing to bypass.

Watering the lawn or garden. Extension guidance from Nebraska and North Dakota State says softened water is not recommended for repeatedly watering plants, lawns or gardens because of its sodium [5][6]. Bypass for the hose, then put the softener back.

Out of salt. Bypass does not fix this. The Fleck troubleshooting table lists an empty brine tank as a cause of hard water, and the fix is to add salt [1]. The water is unsoftened either way until there is salt to regenerate with.

Does the house get hard, unfiltered water when the softener is in bypass?

Yes. Clack’s manual says that in bypass, untreated water is supplied to the plumbing system [2], and EcoWater labels its three-valve bypass position “hard water bypass” [3].

Anything that sits inside the loop is bypassed with the softener. If the sediment prefilter or a carbon filter is plumbed between the inlet and outlet valves, the house gets unfiltered water too; if it is ahead of the loop, it keeps working. Where each part of a system usually goes is covered in our article on prefilters and post-filters.

After a long bypass, expect a few days of harder hot water. EcoWater notes, for a new installation, that the water heater is full of hard water and refills with softened water as hot water is used, so the hot water is fully conditioned in a few days [3]; the same applies after the heater has filled through a bypass.

Does putting the softener in bypass turn off the water to the house?

No. Bypass keeps the house in water; it only takes the softener out of the line. EcoWater says exactly that: bypass valves let you turn off water to the softener but still have water available to the house pipes [3].

The valve that turns off the whole house is the main shutoff. The Florida plumbing code requires a full-open valve on the water distribution supply pipe at the entrance into the structure [4] — see where the main water shutoff valve is. The code also requires a shutoff valve on the water supply pipe to each appliance [4]; it does not mention a softener bypass, which comes from the manufacturers’ instructions [1][3].

Two exceptions to know: the Clack bypass’s shut-off position stops water to the house [2], and closing all three valves of a three-valve loop does the same. Both are mistakes to undo, not a way to shut the water off for a leak elsewhere.

What this means in Clearwater and across Tampa Bay

The photographs on this page are of an outdoor softener in San Antonio, Florida, set partly below grade with a prefilter and three red-handle valves on its piping. Outdoors, the bypass valves sit out in the weather with the softener, and a valve nobody has turned in years can be stiff when it is finally needed.

We install softeners across Tampa Bay and service softener control valves, including systems we did not install. If a bypass will not turn, will not seal, or the house loses water when you move it, call us before forcing it.

FAQ

Sources

We review and cite. We do not reproduce a paper or a manual — follow the links for the originals.

1. [1]Fleck 5600SXT Downflow Service Manual (42684 Rev L) — Pentair · 2018Manufacturer's manual · one maker’s instructions, not necessarily the brand we install. p.3: always provide for a bypass valve if the unit is not equipped with one; the system must be depressurized before removing any connections; start-up step 10 place in bypass, step 11 slowly place the bypass in service position, let water flow into the mineral tank, then slowly open a cold tap until air is purged. p.24 troubleshooting: hard water — by-pass valve is open, close by-pass valve; no salt in brine tank, add salt. p.28 service instructions step 1: with a three-valve bypass first open the valve in the bypass line, then close the valves at the conditioner inlet and outlet; with an integral bypass put it in the Bypass position; step 2 relieve pressure; after the repair return bypass to In Service and be sure to shut off any bypass line. Read 2026-11-09 (PDF text extracted).
2. [2]WS1 & WS1.25 Drawings and Service Manual (V3115-99) — Clack Corporation · 2025Manufacturer's manual · one maker’s instructions, not necessarily the brand we install. p.32: bypass typically used to isolate the control valve from the plumbing system’s water pressure for repairs or maintenance; two plug valves with red arrow-shaped handles that identify flow direction; four positions — normal (handles point with the engraved flow arrows), bypass (both handles point to the centre, control valve isolated, untreated water supplied to the plumbing), diagnostic (inlet with flow, outlet to centre), shut off (inlet to centre, outlet with flow; water shut off to the plumbing system). Read 2026-11-09 (PDF text extracted; revision history to 10/24/2025).
3. [3]Owner’s Manual — Electronic Demand Water Softener, Models ESD2800R25, ESD2802R30, ESD2802R39 (7396800 Rev. K) — EcoWater Systems · 2025Manufacturer's manual · one maker’s instructions, not necessarily the brand we install. p.6: outside faucets should remain on hard water to conserve salt and softening capacity; always install a bypass valve or a 3-valve bypass system, bypass valves let you turn off water to the softener but still have water available to the house pipes. Fig. 3: single bypass valve pull out for Service (soft water), push in for Bypass; 3-valve bypass: soft water service = inlet and outlet open, hard water bypass = inlet and outlet closed, bypass open. Step 9: to prevent excessive air pressure, single bypass — slowly move the stem toward service, pausing several times; 3-valve — fully close the bypass valve, open the outlet valve, slowly open the inlet valve pausing several times. Step 12: water heater filled with hard water refills with softened water, fully conditioned in a few days. Read 2026-11-09 (PDF from EcoWater’s support site, text extracted).
4. [4]Florida Building Code, Plumbing, 8th Edition (2023) — Chapter 6, Water Supply and Distribution — Florida Building Commission / International Code Council · 2023Law / code · §606.1 item 2: full-open valve on the water distribution supply pipe at the entrance into the structure; §606.2 item 3: shutoff valve on the water supply pipe to each appliance or mechanical equipment; §606.3 access to all full-open and shutoff valves; §608.4 names softeners among appliances and devices that treat potable water, waste discharge through an air gap; §611 water treatment units (NSF standards, §611.4 discharge through an air gap). No section of Chapter 6 mentions a bypass for a softener or water treatment unit. Read 2026-11-09 on up.codes (FL Plumbing Code 2023), cited to the FBC sections.
5. [5]Drinking Water Treatment: Water Softening (Ion Exchange), G1491 — Sharon O. Skipton, Bruce I. Dvorak · University of Nebraska–Lincoln Extension · 2014University extension · it is not recommended to repeatedly use softened water for plants, lawns or gardens due to the sodium content; a cold line to the kitchen tap that bypasses the softener is an option for drinking and cooking; about 50 gallons to regenerate. Read 2026-11-09.
6. [6]Water Softening (Ion Exchange), WQ1031 — Tom Scherer, Roxanne Johnson · North Dakota State University Extension · 2022University extension · softened water is not recommended for watering house plants, lawns and gardens due to its sodium content; one kitchen tap can be left unsoftened for drinking and cooking. Revised May 2022. Read 2026-11-09.