Risk of Legionella in Immersion Heater

[Selenus]

Hi all,

Me and my partner have recently moved into a flat that solely uses an immersion heater (think it's a dual one) on economy 7 for water heating.

Since we have an electric shower and a cold-fill washing machine, we turned off the immersion heater as we don't use hot water taps.

My question is, it's come to my attention this might increase the risk of legionella - however, would this affect the cold water tap? Or just water coming out from the hot water tap?

Basically we don't know anything about plumbing, and we don't know whether water (both hot and cold) is stored within the immersion heater, so we're worried about the risk of contaminating water in the heater with legionella and having it contaminated into the water coming through the cold water tap.

Advice much appreciated. Thanks in advance.

Regards.

 

[leesparkykent]

Hi all,

Me and my partner have recently moved into a flat that solely uses an immersion heater (think it's a dual one) on economy 7 for water heating.

Since we have an electric shower and a cold-fill washing machine, we turned off the immersion heater as we don't use hot water taps.

My question is, it's come to my attention this might increase the risk of legionella - however, would this affect the cold water tap? Or just water coming out from the hot water tap?

Basically we don't know anything about plumbing, and we don't know whether water (both hot and cold) is stored within the immersion heater, so we're worried about the risk of contaminating water in the heater with legionella and having it contaminated into the water coming through the cold water tap.

Advice much appreciated. Thanks in advance.

Regards.

You should time the immersion to come up to temperature.

 

[Selenus]

You should time the immersion to come up to temperature.

So you're saying not heating it up risks contaminating the cold water tap too? As opposed to just the hot water tap?

The reason we turned it off is to save on electric bill - we don't use hot water taps, and none of our appliances require heated water. But it's not worth it if it comes at the risk of getting legionella on our cold water taps. That's what we're trying to figure out

 

[Dotty]

Once your hot taps are in regular use the liklihood of legionella forming is highly remote.

I find it hard to believe that you wouldn't use hot water at all, what about hand washing, dish washing etc?

I would leave the economy 7 on, once the water is up to temperature the stat turns the element off anyway.

 

[Selenus]

Once your hot taps are in regular use the liklihood of legionella forming is highly remote.

I find it hard to believe that you wouldn't use hot water at all, what about hand washing, dish washing etc?

I would leave the economy 7 on, once the water is up to temperature the stat turns the element off anyway.

Hand washing is recommended with cold water, not hot water. Bacteria are more likely to breed in lukewarm water than cold water.

We usually do our dishes with cold water - straight after using them. Still beautifully clean. If we cook anything particularly more difficult to wash we can always boil a kettle and mix it with cold water in the sink.
Might sound like hassle, but it makes a big difference (about £30/month) on the electric bill.

Anyway, I know once hot tap water is in regular use the risk will be low.

Our query is different though. We want to altogether circumvent the use of the immersion heater. Would that risk contaminating all the water in the tank, including the one used for the cold water tap?

 

[Dotty]

Cold water is better for cleaning dirt off your hands as it prevents the pores opening and becoming clogged, I'll give you that.

However, the hospitals I work in all advise you wash your hands in hot water with soap to reduce bacterial contamination and cross contamination. Soap and cold water don't do this. Ditto for the dishes, it's not what you can see, it's what you can't that kills you.

But, it's your choice at the end of the day. As long as your water temps are below, and I will need to check I've the correct figure here, 20°c then you'll be ok as far as legionella is concerned.

 

[Dotty]

Yep. Dormant below 20°c.

 

[tamz]

Legionella multiplies between the temperature range of 20 - 50ºC especially if the water stagnates. If you are not heating the hw and continue to run the hw tap as normal the risk of legionella is about the same odds as me winning the lottery on Saturday and i don't buy lottery tickets.
No different to the cold water water sitting in the storage tank that is feeding the cold to your bathroom.

 

[Selenus]

Legionella multiplies between the temperature range of 20 - 50ºC especially if the water stagnates. If you are not heating the hw and continue to run the hw tap as normal the risk of legionella is about the same odds as me winning the lottery on Saturday and i don't buy lottery tickets.
No different to the cold water water sitting in the storage tank that is feeding the cold to your bathroom.

So the likelihood of it is very low? Thank you. It wouldn't be stagnant as we use a fair amount of water every day so it refills all the time.
We were just concerned that if the water isn't getting heated up in the immersion tank, that we might get something in our cold water.

 

[lame plumber]

I wouldnt want to have a cuppa at your place if truth be told, dishes need hot water to be clean, so do your hands..

 

[Selenus]

I wouldnt want to have a cuppa at your place if truth be told, dishes need hot water to be clean, so do your hands..

Not washed my hands with hot water in over 20 years and not had a single incident of food poisoning or gastro. Also FYI, pre-op scrubbing at hospitals is performed in cold water, not warm, not hot.

As for dishes needing hot water, that's absolute bull. Wash and clean your things straight after you use them and it makes absolutely no difference. We have a dish washer and we can use it for things that require it.

Each to their own. Keep to the point of the thread.

 

[tamz]

My dishwasher likes fairy liquid but not the lemon one....so she tells me

 

[lame plumber]

Not washed my hands with hot water in over 20 years and not had a single incident of food poisoning or gastro.

As for dishes needing hot water, that's absolute bull. Wash your things after you use them and it makes absolutely no difference. We have a dish washer and we can use them for things that require it. Each to their own.

you will probably find your immune but it is others you can cross contaminate and cause issues for, why else do kitchens have to have hot water available in toilets and dishwasher have to reach a minimum temp to be safe to use, the bull is from your direction not mine

 

[Dotty]

Closing this thread now before the tinfoil hats get pulled out.