If I were paid to design walking frames, I probably would. I do building services design, refurbishment, maintenance, etc. I avoid legionella infestations by following the simple, established guidlines in L8. You keep hot water hot (>50 degC), you keep cold water cold (
I don't see how setting my (conventional cylinder) thermostat higher will prevent this occurring.
Andy
Wrong.
There is no point because very few items need to be washed at over 40 degrees. At that temperature, it is not worth trying to use hot fill because the amount of hot required is not significant and very little hot water will have been transferred before the level limits are met.
No it doesn't.
USA machines work by using vast quantities of water and unsuitable detergent and temperatures.
100,000 in the UK, which gives me a feel for the risk (not much!) and also suggests the best prevention: dump some bleach on the cold tank before I go on a long holiday. And it is *completely* unrelated to the temperature I use in my hot water cylinder.
No relevance to domestic systems at all.
Sorry, I'm still not convinced by any of that that reducing the temperature of my cylinder to a level where it cannot cause scalding and will improve the efficiency of the system will have any significant effect on my risk from Legionella sp.
On your other post, on the lack of soap and other hand washing facilities in pubs/restaurants - now that is a *real* risk.
Andy
No, you'll have to go and look for yourself, if you're that interested in it. I had assumed the HSE would have some UK-collected data. Maybe not.
That's for detected hospitalized cases. Was it 57% unattrtributed?
No. 60 degC will sterilize the water, You run at less than 60 degC, you increase the risks. Even at 60 degC, the thermostat is usually inaccurate and 1/3 to 1/2 way up the cylinder. The bottom is colder and that's where the little buggers hang out.
Legionella is only one bug, it will often persist under bio-films produced by other organisms e.g. pseudomonas. Legionella bacteria held at 37 degC have a greater virulence than the same legionella bacteria kept at a temperature below 25 degC (from L8). If you have a central TMV set at 46 degCish, you will have favourable conditions at some outlets.
Much the same as UK systems, same risks.
Either you haven't read the extract posted or you've misunderstood.
"Our findings on a limited number (five) of single-family houses suggest that Legionella may occur infrequently in the plumbing fixtures of these buildings."
You do whatever you like. It's an avoidable risk.
Slovenliness of the lowest order.
The message from "Doctor Drivel" contains these words:
What, precisely, is crap?
But hot and cold fill dishwashers are getting like hens' teeth.
Yes, we know about American machines. Used them for years in their native territory and have a couple of American machines on our caravan site. Big, Crude. Relatively reliable. But a moment's thought makes it abundantly clear why many/most/almost all are hot and cold fill. In their native territory they're made to operate off a 110volt circuit and normally off a NEMA 5-15 receptacle. Even if they were to be run off a NEMA 5-20 receptacle there still wouldn't be enough current available for a half-decent heating element for the amount of water that these things consume. And in point of fact, the average American housewife throws everything -- the tea-towels and the dirty underwear in together in a cold or mildly warm wash with a good dose of Javex (bleach). Good for disinfecting everything. Good at burning holes in European clothes. Good at removing colo(u)r from the colo(u)red clothes. And that central agitator is marvellous at disembowelling those underwired pieces of underwear someone mentioned. Historically, they're long-lived machines compared to front-laoders -- hardly surprising as the bearings aren't under much strain. But their hot and cold fill characteristics owe more to American electrical systems than anything else. Paradoxically, of course, they'll quite often have a dryer adjacent to them, running off a 220volt supply, but to the American psyche, a washer is 110 volts and doesn't need much by way of hot water.
The message from Andy Hall contains these words:
Don't forget the Javex (bleach)! They've normally got a bleach dispenser just under the lid and American housewives love to pour in great quantities of the said bleach. I suppose it does help disinfect things a bit, which is just as well, because the soiled underwaear goes in to the same wash in cold or tepid water along with the tea towels :-(
One little question here: how long would the sort of insulation you describe applied properly to pipework in an attic (and similarly high quality insulation applied to a properly installed storage tank) keep the temperature of water within at low enough temperatures to prevent significant growth of legionella on a long hot summer's day when a house is unoccupied and there is therefore no turnover of water in the tank & pipes?
I said a hot fill only dishwasher.
Nope -- they dropped the hot fill to become more economical.
A hot fill dishwasher wouldn't work well. It would polymerise proteins making them pretty impossible to clean off without abrasion. Dishwashers don't use enough water for hot to have come through most pipework before they've reached the fill point. Only two out of the 4 or 5 fill cycles are heated anyway. So a hot fill only dishwasher would be a rather bad idea all round.
Well they do actually. Mine starts filling cold as it doesn't know how hot the hot will be, and then blends in hot. It monitors the tempreature to make sure it doesn't go above 30C which would damage the enzymes in the washing powder, and switches the hot and cold fills on and off appropriately until the required fill level is reached. Typically, it finds the hot is actually cold and stops the cold fill. When the hot starts running hot, the cold fill is combined in again. OTOH, if I've been running the hot tap beforehand, then it continues using both hot and cold to fill.
Even if you are doing a 60C wash, you still need to start it at
30C so the washing powder works properly. Much of the washing ability would be instantly destroyed by a 60C fill.The heating time is an important part of the cleaning process in both a washing machine and a dishwasher (for slightly different reasons), and not something to be avoided. More expensive machines actually take the effort to slow it down.
US washing machines are incredibly inefficient. If they had to heat the volume of water they use from a US socket outlet, they'd take hours to wash.
The message from "Doctor Drivel" contains these words:
Well, you didn't, actually, but I'll accept you meant hot fill only. I'm sure many or most or maybe all dishwashers might allow it in the sense of not physically preventing you from doing it and mabe even allowing you to go through the cycles with only a hot water supply connected,, but it would seem extraodinary to have no control within the machine ver the upper temperature limit of the water used and not only would some cleaning operations be less efficicent, finer china should be raised gradually to the maxinum temperature used hence the pump and spray arms operate before the maximum temperature is reached on the assumption that this will spray first warm water then hotter and hotter up to the temperature determined by the program set.
And yes, before you start I DO know the varioius strictures against putting fine china in a dishwasher. That's a simple rule for people who don't want to know the technical side of it. It's true that dishwasher detergent is hard on fine china. It's also true that older overglaze decoration (gold rims etc.) can be worn off, eventually. In point of fact (and have a word with some of the factory guys from the potteries if you doubt it) with modern overglaze decoration processes and careful use of suitable detergents and , with a suitably gentile program, a dishwasher can be more gentle than hand washing. That does not mean, however, that spraying fine china while cold with water at the maximum temperature attained by some domestic hot water supplies is a good idea.
What make? Most I have come across below 60C just allow only cold in.
Please eff off you are a total plantpot.
Please eff off you are a total plantpot.
Matt, you are wrong again. Sad but true.
Matt, it does.
Neff say you can have both.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.