Legionnaires Disease Precautions

Feb 03, 2022 Last reply: 4 years ago 18 Replies

In my new (to me) house I have a shower that is a "dead leg" in that it is plumbed after the bath with nothing beyond it.



What do I realistically need to do to bring it back into use, it won't have been used for at least a year? I think take the head off and descale/clean, perhaps the chrome flexible water pipe? How long do I need to leave it running and at what temperature? How frequently do I need to re-do this in future, not sure at the moment how much I will use it, I prefer a bath.


I don't know, but when you do run it to clear it out, do so with the shower head off - Legionnaires is only transmitted by aerosol (you can safely drink the water or have a bath in it), so it will be safe without the shower head to spray it.

even bath taps can give some spray.

Don't get Legionella - it's nasty. I had it 30ish years ago.

What kind of shower is it? Electric shower? Hot and cold water mixer/thermostatic valve control? Does the cold water for the shower leg come directly from the mains or is there a cold water storage stage tank in, perhaps, the loft?

If the shower is directly sourced only from the rising mains cold water supply just turning it on will flush it with chlorinated mains water. This may net necessarily be the case for a hot water supply or if the cold water is from a tank.

I'd have thought that this risk was pretty rare. myself. Far more annoying is the way the holes in the head seem to get all blocked up in under a week! Brian

[re shower heads]

Soak the shower head in white vinegar for 24 hours?

Jeff Gaines pretended :

Just running it a few minutes to waste, will be enough. Yes, descale the head - vinegar, citric acid, kettle descaler will do it.

Fit a water softener.

Many thanks for all the replies :-)

I have added the descale and first clean to the jobs list and will ensure it is run regularly after that.

Quite a few at the BBC did too. Wasn't it down to the ventilation system? So unlikely to have similar at home?

Indeed so. Our building supervisor, Jim Morgan, died and my colleague at the next desk was off for 6 months but couldn't stay working in London due to his damaged lungs. He managed to get a job in Geneva where the air is cleaner. He's now retired, but still lives in France.

The spray head on an occasioanlly used shower is a perfect breeding ground for the bacteria. I had to remove the shower at our amateur theatre since the H&S requirement were too onerous.

Brian is in the Thames water area (AFAIK) which knackers kettles and shower heads very quickly.

I have removed the shower attachment from my bath mixer tap today because I never use it and gave the whole arrangement a good soaking with bleach and discovered that the thread used to attach the flexible hose is the same as a 15mm compression fitting so I used one plated nut from an unused ball valve plus a copper end-stop blank to seal it off permanently.

I have occasionally noticed that I get sore eyes and a runny nose after having a bath, which I assumed was something to do with the shampoo I use. The plunger that is lifted to send water to the shower head never shuts off cleanly so some water was always getting into the flexi-pipe.

I am aware of that problem. We have it too (maybe not quite as badly as in London).

Having been brought up in a region where mains water is exceptionally soft, the first time I ever rinsed my hands under a cold tap in London (aged about 19), it felt to me as though it was a flow of iron filings.

I recently replaced my 20 year old water softener which had failed. The new one is cheaper and uses far less salt. In short its ruddy fantastic and after a year nearly all the scaling has gone.

In the 5 years it wasn't working limescale caused about £275 worth of damage.

What make/model are you using now?

The model replacement for what went phut - Tapworks NSC11PRO

formatting link
I hoped it would slot straight in, but the kitchen had been built

*around* the original unit. So it was hard work to modify the copper work to adapt to flexible pipes to allow the unit to be slid into place..

Here it is installed

formatting link

How occasional is occasional? Most showers get used at least a few times a week. But will be unused while away on holiday?

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required