A Whirlpool softener needs one number: the hardness of your untreated supply, adjusted for clear water iron and for potassium chloride if you use it. This page applies Whirlpool's own published rules, shows the arithmetic, and tells you where the control is — and it stops and says so when the model is one those rules were not written for.
Start with your model, because that decides whether a Whirlpool rule can be applied at all. Everything else is your water report.
Showing 250 ppm on a WHES30 with no iron. Enter your own figures to replace it.
15 hardness number to program
Model not covered
Without a model we will not apply Whirlpool's iron or potassium chloride rules. The converted hardness above is still correct arithmetic, but it is not a controller setting.
Confirm this against the hardness section of your own manual before programming. A number that is correct for one control family can be wrong for another.
| Rule | Whirlpool's instruction | Where it is stated |
|---|---|---|
| Unit conversion | Divide a ppm or mg/L result by 17.1 to get grains per gallon. | Hardness Level Programming, step 2. Worked example: 250 ppm ÷ 17.1 ≈ 15 gpg. |
| Clear water iron | Multiply the iron value by 5 and add it to the hardness value. | Owner's manual page 13 for the WHES30/WHES33, and Hardness Level Programming step 3 for controls with a Hardness screen. Worked example: 20 gpg + (2 ppm × 5) = 30. |
| Potassium chloride | Increase the final hardness setting by 25 percent. | Owner's manual page 13. Worked example: a 20 gpg supply is programmed as 25 when using KCl. |
| Rounding | The control accepts whole numbers, so the final value is rounded. | The programming screen itself; the calculator shows the rounding step. |
The iron adjustment is for clear water iron — the kind that is clear in the glass when drawn and turns yellow or brown as it stands, usually within 15 to 30 minutes. Whirlpool states its softeners will not remove ferric (red water), bacterial or colloidal iron. Adding those to the hardness number does not make the softener remove them; it just makes the unit regenerate more often for no benefit.
There is also a ceiling. Whirlpool lists a maximum clear water iron of 8 ppm for the WHES30 and 9 ppm for the WHES33, with maximum supply hardness of 95 and 105 gpg respectively. Above a model's rating the answer is separate iron treatment ahead of the softener, not a bigger number on the screen.
This is the single most common mistake with this setting, and Whirlpool answers it directly: the answer is no. If you set the hardness higher than the supply requires, the unit still delivers the same degree of softness — 0 to 3 gpg — but uses more salt and more water because it recharges more often. Whirlpool describes that as reducing the efficiency of the softener.
Whirlpool also notes there is no "average" or "normal" number to use, because hardness depends entirely on where the water comes from. The number has to be calculated from a test of your own supply, which is what the tool above does.
Conversely, a value set too low means the control believes each gallon carries less hardness than it does, so it waits too long between recharges. Whirlpool lists an incorrect hardness setting among the documented causes of water that is hard only some of the time.
On Whirlpool controls with a Hardness screen, press Program/Select repeatedly until HARDNESS appears on the display, then use the up and down arrows to set the value.
Whirlpool's programming guide walks the full sequence — time, hardness, recharge time, salt
type and salt level — and notes that the salt type screen exists on selected models only.
On the WHES30 and WHES33 the owner's manual documents the same step on page 13, where the
display shows a flashing 25 alongside the word HARDNESS before you
change it.
Whirlpool and Kenmore both describe the same verification: run a regeneration, wait for it to finish — about 2 to 2.5 hours — then test at several cold taps with a hardness strip. Both read 0 to 3 gpg, or 0 to 50 ppm, as soft. GE separately notes that after a correction you should allow a day or so for soft water to flush through the water heater, so a hot tap tested immediately can still read hard even when the change worked.
The rules on this page are Whirlpool's, for Whirlpool equipment. They are not interchangeable with another manufacturer's — the iron multiplier in particular varies, and applying the wrong one gives a wrong number with complete confidence.
The owner’s manual states the iron and potassium chloride rules for the WHES30 and WHES33; the Hardness Level Programming article states them for Whirlpool controls with a Hardness screen. The Kenmore article is listed only to show the same layout on a different brand — do not use it for a Whirlpool unit.
Whirlpool
Water Softener Owner’s Manual — Models WHES30 and WHES33 PDF
Contains the specification table, the hardness and recharge programming steps, the salt bridge procedure, the troubleshooting table and the error codes. The model code shown in diagnostics is L30P for the WHES30 and L33P for the WHES33.
Whirlpool
The ppm-to-gpg conversion, the clear water iron multiplier and the potassium chloride adjustment, as Whirlpool states them.
Whirlpool
Covers time, hardness, recharge time, salt type and salt level. Whirlpool does not list model numbers on this page and states some steps are for select models only, so check it against your own owner’s manual.
Kenmore
Each link goes to the manufacturer or organisation that published it. We do not host copies.