Direct answer: A Gemline softener is a NuGen Fusion XT, and its control regenerates on its own when the metered water use reaches the capacity it calculated from the hardness setting, or when the day override (factory set to 14 days) runs out, whichever comes first. It regenerates at 2:00 a.m. unless the installer changed that. To add a regeneration tonight, press and release REGEN until “REGEN TODAY” flashes. To start one right now, hold REGEN for three seconds; an immediate regeneration cannot be cancelled. If the brine tank was empty, the manual says to fill it and wait at least two hours first.
Publisher boundary: Water System Guide is an independent research publisher, not a Gemline or NuGen dealer. This page uses the NuGen Fusion XT owners manual (footer revision 5/10/2012), which the 2023 Gemline brochure names as the manual for Gemline softeners, and the brochure itself. Both were reviewed October 15, 2026. Settings changes beyond the owner level are for the installer.
How the control decides when to regenerate
The manual says the manufacturer presets the cycle times, salt dose, exchange capacity and brine refill time. The dealer and installer set three things: hardness, days override and time of regeneration (Fusion XT manual, PDF page 4).
- Hardness. Entered in grains per gallon, default 20, range 1 to 150. “The manufacturer has preset the unit so that the gallons between regenerations will be automatically calculated after the hardness is entered.” The hardness “can be increased if soluble iron needs to be reduced” (manual, PDF page 9).
- Days override. Factory set to 14 days, the “maximum number of days between regenerations.” It can be 1 to 28 days or OFF. At OFF, regeneration is “based on gallons used only.” At any number, the control regenerates on that day “even if a sufficient number of gallons were still available.”
- Time of regeneration. Default 2:00 a.m., set by hour and minute.
So the softener meters the water it treats, counts down the gallons it can still soften, and schedules a regeneration for the next set time once the count runs low or the day limit is reached. The brochure describes the same process in plain terms: when the resin “becomes saturated with hardwater minerals, the water softener system automatically goes into regeneration” (Gemline brochure, PDF page 1).
What the display tells you
During normal operation the first display is the time of day. Pressing NEXT scrolls through days remaining, capacity remaining in gallons and the current flow rate. “If the system has called for a regeneration that will occur at the preset time of regeneration, the words REGEN TODAY will appear on the display.” When water is flowing, “Softening” flashes if a meter is installed (manual, PDF page 11).
If “Softening” never flashes while a tap is running, the control is not counting water, and it will regenerate only on the day override. That is one of the causes the manual lists for a softener that does not regenerate automatically (see the troubleshooting section below).
What happens during a regeneration
The brochure describes the steps: “Brine water is drawn into the resin tank and rinses the hardwater minerals off the resin and down the drain. Once the resin is free of hardwater minerals, fresh water rinses the remaining brine water out of the system leaving the system refreshed and ready for service.”
The manual’s start-up procedure names the positions the valve moves through: Backwash, the brine draw, a rinse and Fill, in which “water [runs] into the brine tank and prepare[s] it for the next regeneration” (manual, PDF page 13). During a regeneration “the display will change to include information about the step of the regeneration process and the time remaining for that step.” The control “runs through the steps automatically and will reset itself to provide treated water when the regeneration has been completed” (manual, PDF page 12).
Two things owners notice:
- Untreated water during the cycle. “If there is a demand for water when the system is regenerating, untreated water will be used.” That is why the default time is 2:00 a.m.
- Water to the drain. The data sheets give the maximum flow to drain during regeneration: 2.7 gpm for the XT-32C, XT-48 and XT-60, 3.2 gpm for the XT-70 and XT-70ER, and 4.2 gpm for the XT-90 (manual, PDF pages 33–34). The manual says to “be sure that the drain can handle the backwash rate of the system” (manual, PDF page 6). Only the XT-70ER sheet gives a total water figure, 61.9 gallons per regeneration (manual, PDF page 34).
How to start a manual regeneration
The manual calls any regeneration started by the owner a manual regeneration, useful when “there may be a period of heavy water usage because of guests or a heavy laundry day” (manual, PDF page 12).
| What you want | What to press | Can you cancel it? |
|---|---|---|
| Regenerate tonight at the set time | Press and release REGEN; “REGEN TODAY” flashes | Yes, press REGEN again |
| Regenerate now | Press and hold REGEN for three seconds | No, “the request cannot be cancelled” |
| Two regenerations within 24 hours | Press REGEN once (“REGEN TODAY” flashes), then hold REGEN for three seconds | The immediate one cannot be cancelled |
The double regeneration is described on the pre-installation page: “Once the control valve has completed the immediate regeneration it will do another one at the next scheduled regeneration time” (manual, PDF page 4).
Before you press REGEN
- Check the salt. “For softeners, if brine tank does not contain salt, fill with salt and wait at least two hours before regenerating” (manual, PDF page 12). The brochure and the data sheets say the manufacturer “recommends the use of pelletized sodium chloride salt”; the brochure also says the systems “can regenerate with sodium or potassium.”
- Check the bypass. The bypass valve has four positions. In the normal position the control valve can “isolate the media bed during the regeneration cycle.” In the bypass position the control valve is isolated and untreated water goes to the house (manual, PDF page 6). A softener left in bypass will regenerate but will not treat water.
- Plan for the noise and the drain. Expect water running to the drain for the length of the cycle.
Regeneration at start-up and after service
The manual’s start-up procedure is a guided regeneration done by the installer. With the bypass in the bypass position, water is poured into the brine tank to the top of the air check valve, REGEN is held to start Backwash, and the inlet is opened “very slightly” to expel air. “CAUTION: If water flows too rapidly, there will be a loss of media out of the drain.” The installer then steps the valve through brine, rinse and fill with the REGEN button, loads the brine tank with salt while it fills, and finishes with a sanitizing regeneration (manual, PDF page 13).
The sanitizing step is printed in capitals: “SANITIZE! ON INITIAL STARTUP AND AFTER SERVICING THE VALVE.” The dose is “two ounces of 5.25% household chlorine bleach” per cubic foot of resin, added to the brine well before a full regeneration. The data sheets list 1 cubic foot of resin for the XT-32C, 1.3 for the XT-48, 1.7 for the XT-60, 2.18 for the XT-70 and XT-70ER and 2.5 for the XT-90. By our arithmetic that is about 2, 2.6, 3.4, 4.4 and 5 ounces of bleach. Check local codes, which the manual says “may also specify sanitization methods.”
How much salt each regeneration uses
The salt dose is preset by the manufacturer, and the data sheets show the capacity each dose buys (manual, PDF page 33):
| Model | Low dose | Medium dose | High dose |
|---|---|---|---|
| XT-32C | 18,000 grains at 4.5 lb | 23,000 at 9.0 lb | 28,000 at 15.0 lb |
| XT-48 | 23,500 at 6 lb | 29,500 at 11.0 lb | 36,000 at 19.5 lb |
| XT-60 | 31,000 at 8 lb | 39,000 at 15.0 lb | 47,000 at 25.5 lb |
| XT-70 | 39,000 at 10 lb | 50,000 at 19.0 lb | 60,000 at 32.0 lb |
| XT-90 | 45,000 at 11.5 lb | 58,000 at 22 lb | 69,000 at 37 lb |
The manual does not say which of the three doses the factory preset uses. Ask the installer, because it sets both how often the softener regenerates and how much salt each cycle takes. The Gemline ownership cost guide works through what these doses mean for salt use.
When regeneration goes wrong
The troubleshooting table lists regeneration problems with causes and fixes (manual, PDF pages 14–16). The owner-level items are in the first column; anything involving pistons, seals, injectors or the PC board is for a technician.
| Symptom | Owner-level causes in the manual | Technician-level causes |
|---|---|---|
| Regenerates at the wrong time of day | Power outage; time of day set wrong; regeneration time set wrong | Control set to “NORMAL + on 0” |
| Does not regenerate on its own, but does when REGEN is held | Bypass in bypass position; meter not connected; incorrect programming | Stalled meter turbine; meter wire; defective meter |
| Does not regenerate even when REGEN is held | None listed | Broken drive gear, drive cap or piston rod; defective PC board |
| Uses too much salt | Leaking fixtures exhausting capacity; system undersized | Refill or program settings |
| Salty water after regeneration | Low water pressure (must stay at least 25 psi); restricted drain line | Wrong injector size |
| Too much water in the brine tank | Kinked or restricted drain line | Plugged injector; seal or stack damage; missing refill flow controller |
| Does not draw brine | Drain line too long or too high; low pressure | Plugged injector; faulty regenerant piston; air leak |
| Water running to drain | Power outage during a regeneration: “upon power being restored control will finish the remaining regeneration time” | Seal, stack or piston failure |
A flashing time of day means the power was out. The manual says to reset the clock and that “if PC Board has battery back up present the battery may be depleted.” The site requirements on page 5 say “Batteries are not used.” The two statements cover different board versions; reset the clock either way. If the display shows E1, E2, E3 or an Err number instead, see the Fusion XT error code guide. If the water is still hard after a full regeneration, work through the Gemline not-softening checklist.
Frequently asked questions
How do I force a Gemline water softener to regenerate?
Press and hold REGEN for three seconds. The Fusion XT manual says it “will begin to regenerate immediately” and that the request cannot be cancelled. Fill an empty brine tank and wait two hours first.
How often does a Gemline softener regenerate?
When the metered gallons reach the capacity calculated from the hardness setting, or after the days override, factory set to 14 days, whichever comes first. The regeneration runs at the set time, 2:00 a.m. by default.
Can I use water while a Gemline softener regenerates?
Yes, but the manual says untreated water will be used during the cycle. That is why regeneration is set for a time when the household is asleep.
Why does my Gemline softener regenerate at the wrong time?
The manual lists a power outage, a wrong time of day and a wrong regeneration time as the usual causes. Reset the clock after any outage.