What water should you put in a steam iron?
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Part of our hard water guide
Makers disagree. Here is what their own UK pages say goes in the tank, and why your tap matters. You can check yours with a 20-in-1 test strip.
Short answer: Use the water named in your iron's handbook, because makers differ. Tefal's UK manual says tap water, or half tap and half distilled in very hard water. Morphy Richards says distilled, deionised or demineralised for its cordless irons. The Drinking Water Inspectorate cites the WHO as saying 200 mg/l or more produces scale.
By Andrew Tomlinson, WaterKit · Last reviewed 29 October 2026
What water should you put in a steam iron?
The water your own handbook names, because the makers we read disagree. In the sources we read, which were maker pages, Which? and the Drinking Water Inspectorate, we found no UK official guidance on which water an iron needs. Here is what Tefal's UK manual page, Rowenta's and three Morphy Richards support pages say.
| Maker and model | Water it recommends | Water it says not to use |
|---|---|---|
| Tefal, Maestro steam iron | Untreated tap water. For very hard water, no more than 50% tap water, with 50% distilled | Additives such as starch, perfume or softener, dryer, fridge, air conditioner and rain water, and shop-bought demineralised or distilled water used pure |
| Rowenta, steam station | Untreated tap water, or 50% tap and 50% distilled if very hard | Scented or softened water, dryer, fridge, battery, air conditioner and rain water, and boiled, filtered or bottled water |
| Morphy Richards, cordless irons | Distilled, deionised or demineralised water | Tap water, especially in hard water areas, plus anything with sugar, starch, fragrance or additives |
| Morphy Richards, one steam generator | 50% tap and 50% deionised, distilled or demineralised water | More than 50% deionised, distilled or demineralised water |
So Morphy Richards gives opposite advice for two models.
Can you put tap water in a steam iron?
In many irons, yes, according to Tefal and Rowenta, but hard water makes scale build faster. The Drinking Water Inspectorate (DWI) says hard water scales kettles, electric irons and other appliances, which shortens the life of heating elements and makes appliances less efficient. Which? says limescale can build up quickly in hard water areas, especially if you fill straight from the tap.
The DWI classes water as soft up to 100 mg/l of calcium carbonate, slightly hard to 150, moderately hard to 200, hard to 300 and very hard above that. It cites the World Health Organization as saying 200 mg/l or more will produce scale.
Can you use distilled or demineralised water in a steam iron?
Sometimes, and often only as a mix. Tefal and Rowenta suggest 50% tap and 50% distilled for very hard water, Morphy Richards' steam generator page says never more than 50% distilled, and its cordless iron page says to use distilled, deionised or demineralised water alone. If the distilled half has no dissolved minerals, a 50/50 mix would halve your tap's hardness (our arithmetic).
Can you use tumble dryer water in a steam iron?
Tefal and Rowenta say no. They list clothes dryer, fridge and air conditioner water among the types never to use, because it can contain organic waste or minerals. Whether dryer water counts as distilled is covered in our tumble dryer water guide.
Why is my steam iron leaking brown water?
The makers point to scale, additives or leftovers inside the iron. Morphy Richards' general page calls brown water an effect of limescale mixing with impurities and a sign the iron needs descaling. Its page for one steam generator says brown water is not automatically normal or proof of limescale. Tefal and Rowenta name additives, chemical descaling products in the tank, and soap or chemicals left in poorly rinsed or new clothes. If the cold tap runs brown into a clear glass too, see our brown or cloudy water guide.
Do you need water in an iron, and how do you fill it?
Only for steam. Tefal says its steam irons can iron dry, with the steam control set to Dry and no need to fill the tank. For filling, Tefal says to unplug the iron first, set the steam control to the no-steam position, not fill beyond the MAX mark, and empty the tank after use.
What one reader found
In a 2012 Mumsnet thread, a poster said her steam generator iron spewed brown stuff while she ironed a white sheet. One replier said earlier irons did the same after a while, that descaling might clear it only briefly, and that she now fills hers with de-ionised water only. In her words, "I live in a hard water area and tap water just ruins irons!" Others suggested the self-clean option, descaling, or asked whether it was rust. The original poster replied that she lives in Ireland and did not think her water was hard. It is one person's experience, not proof of a cause. Shared on Mumsnet
Why might your tap not match the hardness figure for your area?
The DWI says hardness varies with local geology, its map shows only typical hardness for England and Wales, and for an accurate measurement you should ask your water company.
“Area figures are averages, so I would always check the water at the tap you actually fill from before deciding what to put in your iron. If you have a softener, check the handbook as well, because one tap in the house can differ from another.”
How can you check your own tap before choosing the water?
Test the tap you fill the iron from. Fill a clean glass or cup, dip one strip, wait 30 to 60 seconds and match the pads to the chart, or enter the colours in our free results checker (scan the QR code on the chart, no app or account needed).
Reading the steps against the DWI bands is our own comparison, because the pad's unit basis is unconfirmed. On our reading, steps 0, 25 and 50 sit within the DWI's soft band (up to 100), 100 at its top, 250 in the hard band (200 to 300) and above the 200 mg/l the DWI cites from the WHO for scale, and 425 in the very hard band. The strip cannot show additives, residue or scale inside the iron, or which water your model needs. Its iron pad starts above the UK limit, so it will not explain brown marks. We do not claim the rapid bacteria test for water going into an iron.
The area figure is an average, and because hardness varies with local geology your tap may differ from it. The hardness pad is the one that matters here, and a step higher than your area band would indicate harder water and faster scale in an iron, while a lower step would indicate softer water. Best pack: 20 strips, enough to test your tap now and again later, £5.99 (or £10.99 with a bacteria test), with free 2nd Class delivery on every order. See the kit
Your steam iron water questions
What water to use in steam iron? What water should I use in my steam iron? What water should I put in my iron? What water to use in iron? What water should you use in a steam iron? What water do you put in an iron? What water should I use in my iron? What water to put in iron?
The water your handbook names. UK makers' pages split between tap water, a tap and distilled mix, and distilled-type water only.
Can you put tap water in an iron? Can you use tap water in an iron? Can you put normal water in an iron?
Tefal and Rowenta say their irons are designed for tap water, while Morphy Richards' cordless irons say to avoid it.
Why is my iron leaking brown water? Why does my iron leak brown water? Why is my steam iron leaking brown water?
Makers point to limescale, additives, or soap and chemicals left in clothes.
Do you need to put water in an iron? Do you have to put water in an iron? Do you need water in an iron?
Only for steam. Tefal says its steam irons can iron dry.
How to put water in iron? How to put water in an iron?
Tefal says to unplug it, set the steam control to no steam, fill no higher than the MAX mark and empty the tank after use.
Sources
- Drinking Water Inspectorate, Water Hardness / Hard Water (undated page; hardness bands in mg/l calcium carbonate, scaling in electric irons, the WHO 200 mg/l scale value, local variation, softeners; read 29 October 2026).
- Tefal UK, User manual and frequently asked questions, Maestro FV3776G0 ("Which water should I use?", dry ironing, filling, brown spots; undated page; read 29 October 2026). Paraphrased.
- Rowenta, User manual and frequently asked questions, Perfect Steam Station DG8980F0 ("What water to use?", brown streaks; undated page; read 29 October 2026). Rowenta and Tefal show the same parent group in their page footers, so these two are not independent. Paraphrased.
- Morphy Richards UK Support, Can I Use Tap Water in My Morphy Richards Cordless Steam Iron? (models 303250 and 303251; undated page; read 29 October 2026).
- Morphy Richards UK Support, SteamElite Plus (332013), Brown or Discoloured Water from the Soleplate (the 50/50 mixture; undated page; read 29 October 2026).
- Morphy Richards UK Support, Why is My Steam Iron Releasing Brown Water? (undated page; read 29 October 2026).
- Which?, Why you need to clean your iron regularly (yes, really!) (published 29 November 2019; limescale and filling from the tap; we read the opening sections; read 29 October 2026). Which? is an independent consumer organisation, not an official body. Paraphrased.
- Mumsnet, Iron spewing out brown stuff (Housekeeping forum thread, April 2012; one reader's account, not evidence of cause; read 29 October 2026).
- WaterKit, Water Test Kit (20-in-1 strip, 30 to 60 second read, optional rapid coliform test read after 24 to 48 hours, free 2nd Class delivery on every order) and results portal. The hardness step comparison and the 50/50 arithmetic are WaterKit's own reading of the colour chart steps and are not maker or DWI figures.
Contains public sector information licensed under the Open Government Licence v3.0.