I just received a question related to connecting up a washing machine, which I’d like to answer publicly so as to help more than one person. People are generally aware that hard water is bad for washing machines so it seems on the face of it to be a good idea to connect one to a water supply which is being softened.
“I live in a hard water area and I already have a salt softener fitted. I’m in the process of buying a new Miele washing machine who recommend not to connect it to softened water supply for reasons similar to those that you give about detergent residue and rinsing (Is it OK to connect a washing machine to a full scale water softening system?)
I could connect it to either the raw hard mains or the softened supply. Surely the advantages of using the softened supply to reduce the damage caused by limescale build-up would to me seem to outweigh the cons of having to rinse a few more times. Would that be your view or would you go over to raw mains?”
Here’s a quote from a few different washing machine manufacturers -
“Too little detergent results in lime scale on the heating element”.
This surely means that using enough detergent should not result in lime scale on the heating element?
As far as I’ve ever been told, washing machine detergent contains all the water softening agents you need. As long as you use a decent quality detergent and use the correct advised amount for your hard water you shouldn’t need anything else.
You get limescale in your kettle, taps and shower because you are heating up plain (hard) water. However, in your dishwasher and washing machine specialised detergent contains water softening agents to allow the detergent to work and to protect the washing machine from limescale.
Related: Is it OK to connect a washing machine to a full scale water softening system? |Should I use Calgon anti limescale tablets or other such products?
If anyone knows any different I’ll be glad to amend my advice on this subject.
Interesting, I’m sure this will surprise many people who fit softeners in the sole belief it is better for their machine and cheaper in detergent than using hard water. Hard mains it is then (for now). Another aspect to consider were you to consider going down the softened route is the pressure loss through a softener (this can easily be 1bar) which may then leave you with insufficient pressure at the machine.
Thanks Neil: I think the intended advantage of a water softener on the entire water supply is to combat limescale in the immersion heater, hot taps, kettles, coffee makers & showers etc and not white goods appliances which should be protected by their detergent.
Many water softeners use ion exchange, where sodium ions replace calcium & magnesium ions to soften the water. The effect of increased sodium going into the washer may result in agressive reactions with metalic items such as the drum, shaft and spider eventually leading to premature mechanical failure.
I agree with Bob above, nearly all the probs I have come across on drum shaft spiders ( I’m working mostly on a german brand who have well constructed drums) have occured where the machine is connected to a water softner (using salt – not magnetic, electrical) and in most cases they have had low usage i.e an older couple, no kids doing 1 -3 loads a week .
My theory is this; the softening is achieved by exchanging calcium and magnesium ions with sodium ions. When you start to wash with this and add chemical alkilis (detergent) and heat you get a fairly agrresive solution which starts to degrade the metal especially the shaft spider alloys. Then they don’t use the machine for say 4 days, and in the meantime the residue water starts to evaporate leaving a much stronger solid residue probably high in Sodium which is an alkaline metal and a very reactive metal ( back to chemistry lessons) which continues to do the damage at an increasing rate.
With higher usage it appears to be less of a problem as the water never really evaporates off , as it’s in fairly constant use and also if it does happen after say 12 years of heavy use would you worry about it? possibly not.
I would advise it’s better to steer clear of these types of softners on a washing machine and just use the correct amount of detergent that is good quality and you should be fine as Andy says. You could also employ a ‘one shot’ descaler ands use it once or twice a year and is would still be cheaper than the big brand descaler that we’re asked to use every wash.
I’ve been using water-softeners since 1984, and supplying my dishwasher and washing machine from them. The washing mnachine was replaced a few weeks ago due to motor failure, after 28 years of use. It had never gone wrong otherwise, and has always been free of limescale and soap deposits. The clothes come out clean and the towels and other items are soft and fluffy (which you can’t say for towels washed in hard water).
I have seen no evidence of ill-effects from softened water.
Thanks for your contribution John. Using a washing machine with an artificially softened water supply should not damage the washing machine, but wash results can be affected due to the detergent not dissolving properly and leaving detergent residue on laundry although it seems you have noticed no issues.
I don’t understand why you say the detergent might not dissolve properly. I find everything dissolves better in softened water, so it doesn’t leave soap scum in the bathroom, for example, and it cleans away existing soap residue. Also you need less detergent. Have you seen any independent scientific tests on soap powder and softened water that I can look at?
Hi John. I was quoting from washing machine manufacturer’s advice on the subject. Detergent already has sufficient water softener built into it, so if you use the correct amount of detergent combined with already softened water, the water can be too soft. Detergent can over foam creating too many suds. This will cushion clothes from each other and potentially reduce cleaning efficiency.
The problems with dissolving would presumably be if the water was too soft rather than just being soft, so maybe you get the combination of not all the detergent dissolving properly but the detergent that does dissolve creates too many soap suds.
If you reduce the amount of detergent used (and don’t go on what they recommend) then you may not have any problems.