Electric showers - the good, the bad and the ugly

[Kim]

It's basically a tradeoff between the flow regulation problem and the running out of stored hot water problem.  Combis work best with small households (nobody can flush the loo if you've locked yourself in with it to have a shower), hot water tanks with predictable use patterns.  Hard water kills everything eventually.

A pumped shower fed from a BFO tank of seriously hot water is by far the best.

[hellymedic]

I SO regret doing away with my cylinder!

Best PSO showers I recall were in the locker rooms at the (Royal) Hallamshire Hospital. This was in the basement of a tallish tower block. Sheffield water is very soft and hospital boilers are awesome!

[Cudzoziemiec]

Our Mira shower packed up a year or so ago. Plumber said it was so old, they hadn't made that model for yonks. It was there when we moved in, um, yonks ago (about 2011 maybe). But that doesn't really strike me as so amazingly long. New shower is also Mira, seems pretty powerful and certainly temperature is stable and flow unaffected by any other water use. Water is hardish (deposits fine red Mendip sandstone on shower walls).

Coldest shower I ever remember was in a backpackers in, of all places, Fiji. Yes, you need the tropics for freezing cold water!

[Kim]

Sheffield water is very soft

Spoken like a Londoner.

Sheffield water (and indeed Birmingham water, which is smuggled across the border from Wales)  is pretty much optimal, I reckon.  Hard enough that you can wash the soap off, but easy on the plumbing.

Very soft water is amusing as a novelty, but becomes boring very quickly.  Especially when combined with  a) shampoo  and  b) 7500W electric showers.  For bonus points, Manchester water is soft *and* tastes minging.

At the other end of the spectrum, Canterbury Carbonate is a work of Stan, especially when combined with vegan soap.

[ian]

Our Mira shower packed up a year or so ago. Plumber said it was so old, they hadn't made that model for yonks. It was there when we moved in, um, yonks ago (about 2011 maybe). But that doesn't really strike me as so amazingly long. New shower is also Mira, seems pretty powerful and certainly temperature is stable and flow unaffected by any other water use. Water is hardish (deposits fine red Mendip sandstone on shower walls).

Coldest shower I ever remember was in a backpackers in, of all places, Fiji. Yes, you need the tropics for freezing cold water!

Malawi. Straight out of a well. It wasn't even warm outside. They heard me scream in Zambia. Psycho had nothing on that shower scene.

Our megashower is digital, you set the temperature on a dial and it's like a kind of magic. The only downside is the little flashing gizmo light that indicates when proper toastiness has been achieved died. The hardship. Basically wait five or so seconds until there's steam on the cubicle door and dive in. When I see other people's excuses for a shower I laugh and then I cry.

My policy of completely ignoring water hardness has served me well.

[hellymedic]

Glasgow water is also soft enough to poison the natives with their lead pipes. (Not a Cluedo scenario...)
But my hair was nicest in Sheffield!

[De Sisti]

For bonus points, Manchester water is soft *and* tastes minging.

Coming from Manchester, I agree that the 'corporation pop' is soft. When I lived there a few years ago
we had visitors fill some bottles with the stuff to take back to London, as they thought it tasted devine. 

[SoreTween]

Glad I read this thread, we've been considering getting a combi so that we can get rid of the tank and have space for a bath in our upstairs bathroom shower room.  I shall have to look into the low flow abilities of the boiler currently top of the list.

The distribution box is immediately below the bathroom

Does your shower drain downstairs or horizontally between the floors?  If the former you've got the ideal setup for Drain Water Heat Recovery.  It's a year since I looked into them but back then there were three types:
1) Vertical pipe in pipe, the only type legal in the UK
2) Horizontal, becoming a thing in Trumpistan
3) Horizontal compact for fitting under a shower tray, some European manufacturers.
See EcoDrain for example.

[ScumOfTheRoad]

Glasgow water is also soft enough to poison the natives with their lead pipes. (Not a Cluedo scenario...)
But my hair was nicest in Sheffield!

Indeed. Followign from the example of my parents and grandparents, I still run the cold tap a bit before usign the water. Even though I am no longer in Glasgow.
Its a hangover fromt he days of lead pipes - you flush the first bit out which has been sitting in the pipes.

[mrcharly-YHT]

Glad I read this thread, we've been considering getting a combi so that we can get rid of the tank and have space for a bath in our upstairs bathroom shower room.  I shall have to look into the low flow abilities of the boiler currently top of the list.

The distribution box is immediately below the bathroom

Does your shower drain downstairs or horizontally between the floors?  If the former you've got the ideal setup for Drain Water Heat Recovery.  It's a year since I looked into them but back then there were three types:
1) Vertical pipe in pipe, the only type legal in the UK
2) Horizontal, becoming a thing in Trumpistan
3) Horizontal compact for fitting under a shower tray, some European manufacturers.
See EcoDrain for example.

That looks a simple good idea. Not sure if we could fit one, I suspect the cold water feed comes down from above and I know the drain is horizontal below the bath. I'll check the cold feed in. Might be able to fit something myself, access to the drain is just by bath side panel.

[Cudzoziemiec]

We have a combi boiler and an ordinary mixer tap shower.
Everything works on water mains pressure, which is HIGH here.

The combi boiler only heats the water if the hot tap is at least nearly fully open.
Opening the cold tap reduces water pressure available to the boiler.

If I'm very lucky, I can get a torrent at the right temperature. I need to adjust the taps VERY finely. I can't have a warm, gentle trickle. This bugs me more in the kitchen for washing the dishes than it does in the bathroom for washing my hair but

I HATE MY COMBI BOILER!
I HATE GETTING WET BECAUSE I NEED MAINS PRESSURE TO FIRE THE HOT WATER!
I HATE WAITING AGES TO GET HOT WATER IN THE KITCHEN!
I DISLIKE HAVING WATER THAT IS HARDLY ABOVE HAND HOT!
David can't wash his hands in hot water upstairs if I repeatedly flush the downstairs loo.

I miss my hot and cold tanks. My gas bills might be a bit less but I'd like better control and availability of my hot water.

Sounds to me as if something is wrong in your boiler. Can you (or a plumber!) adjust the point at which the hot water comes on? It really shouldn't need the tap nearly fully open.

[Aunt Maud]

Here at cobweb central, we have a condensing system boiler (with a 30 litre, or is it 45 litre, tank) and some clever soul recently installed an insulated and pumped hot water loop to the kitchen and bathroom taps. I think it's super dooper.

We installed a combi boiler in the Somerset pile of rubble and it was rubbish.

[Quisling]

Glad I read this thread, we've been considering getting a combi so that we can get rid of the tank and have space for a bath in our upstairs bathroom shower room.  I shall have to look into the low flow abilities of the boiler currently top of the list.

The distribution box is immediately below the bathroom

Does your shower drain downstairs or horizontally between the floors?  If the former you've got the ideal setup for Drain Water Heat Recovery.  It's a year since I looked into them but back then there were three types:
1) Vertical pipe in pipe, the only type legal in the UK
2) Horizontal, becoming a thing in Trumpistan
3) Horizontal compact for fitting under a shower tray, some European manufacturers.
See EcoDrain for example.

Exploring the Eco-drain idea, and if I've got my maths right:
* Energy required to heat water = 4200J/kg/C
* 1kg water = 1 litre.  Let's say the average shower is 40 litres.
* let's assume water enters the shower at 50C and leaves at 40C.  Energy remaining in water entering drain is:
40 x 40 x 4200 / 3,600,000 = 1.86kWh.
* Let's now assume 46% of that heat is recoverable, therefore 0.86 kWh of heat is recovered.  If you have an electric shower and your electricity costs 12p/kWh then the Eco-drain saves you 10.3p/shower.  However, if you are using gas it's saving you perhaps a quarter of that.

Showers can have a flow rate of 3 - 30 litres per minute with the average shower apparently 8-12 minutes (far less for us baldies, especially if you turn off flow while you soap up).  A shower therefore ranges from 24 to 360 litres!  Assuming an aerating shower head limited to 9 litres/minute that gives a volume range of 72 to 108 litres.  Both of which seem high (our household of four uses a modest total of 75 litres/person/day including 2 showers and 1 bath on the average day).

On the face of it the Eco-drain seems to make sense IF you have an electric shower.  However, is it really 46.6% efficient?  The last bit of heat it recovers in each shower pre-heats incoming water which isn't used for example.  It also has lots of small bore pipes which won't much like hard water!  I think I'm also optimistic in assuming water enters the drain at 40C as a good deal of heat will be lost running down the shower enclosure, falling through the air etc.  Interesting though.

[SoreTween]

That looks a simple good idea. Not sure if we could fit one, I suspect the cold water feed comes down from above and I know the drain is horizontal below the bath. I'll check the cold feed in. Might be able to fit something myself, access to the drain is just by bath side panel.

Looks like things have moved on a fair bit in a year (or maybe my DuckDuckFu has improved). It's an annual research project when the incoming water is at it's coldest and the shower is classic kitten piddler.

Lot's of options legionella checked in the UK now.  The bad news is in the FAQs they are not rated for installation with an electric shower, only thermostatic mixers.  That's because as the drain warms up the delivery temp goes up.  In my own home I'd use one with an electric thermostatic and cross my fingers that regulations catch up with sanity before I come to sell the house.

[mrcharly-YHT]

I've just had a rethink about ecodrain and no way is it a good idea for us if there are small bore pipes involved.

Long hair + smallbore pipe = disaster

We can clog up a standard 38mm drainpipe in a week.

[Quisling]

I've just had a rethink about ecodrain and no way is it a good idea for us if there are small bore pipes involved.

Long hair + smallbore pipe = disaster

We can clog up a standard 38mm drainpipe in a week.

The small bore is the inlet mains cold water tubing.  The outlet drain is "standard" pipework - albeit it needs to be standard copper pipework to get the heat exchange so it'll be at least 32mm internal diameter or more like 50 if in the horizontal sort of installation.

[Nutbeem]

Triton - seem to be market leader - I've just installed one with a black casing for my daughter ... looks great.  I'm not sure you'll feel the hit that much on the electricity, you're only using power for instant hot water while the shower is on -  depends on the main system for hot water.

Rob

We have had electric showers for over 10 years, all Triton.  About every 18 months to 2 years they pack up and either need replacing under warranty or I have to buy a new one. 

I don't think there is anything inherently wrong with electric showers or Triton, I think its us.  The two adults in the house use the shower each day for about 10 minutes.  The Grumpy Teenager can be in there for an hour    I suspect herein lies the problem.

In May we are having a new bathroom and boiler amongst other stuffs.  The boiler will be a 35kw combi and the shower will run off it.  The Grumpy Teenager will have Grumpy Adults pounding on the bathroom door if she's under the shower for too long.  I'm hoping we will have a more reliable showering experience and lower energy bills.

We experienced the same until we discovered the benefits of Cold Water Flush.

By flushing all the hot water out of the showers heating tank you reduce the build up of lime scale which in turn prolongs the showers life significantly. You can achieve the same with a more basic shower by letting it run cold before turning it off, but having it as a built in automatic function is a better option.

As per my previous comment our Mira was still working after more than 10 years and has only been replaced as we have just had the bathroom gutted and re-fitted & it seemed sensible to replace everything including the shower.

[CrinklyLion]

Now I need to find a plumber in York . . .

Chap (recommended to me by CU and CA) that sorted my extremely leaky rad in the bathroom recently (by replacing it) was lovely.  Not cheap, and I had about a three week wait from him coming to spec the job to him coming and doing the work (which was a little quicker than he had said, but he managed to fit me in on a Saturday) but lovely.

[mrcharly-YHT]

Could you PM a name? I've used Colin Badger a long time ago but not sure if he is still around (or as good as he used to be).