Why you can (probably) do better than an electric shower

[@seismic6402]

In a one bathroom situation, relying solely on the gas boiler can lead to occupants not being able to have a hot shower if the boiler packs in or if the gas supply is interrupted. In a two bathroom situation it seems to make sense to have the main bathroom shower running off the boiler and another shower somewhere else on electric.

[@juliaevans9521]

I found this video fascinating as my local Council have insisted that installing a power shower in my flat is the best way to resolve the lack of water pressure to the bathroom (shower head AND taps primarily), instead of supplying and fitting a pump by the hot water tank which is already on 24/7 (I pay a fixed fee for hot water).

[@RootsKent]

Short answer: power shower may be better for the shower in your flat than pumping all the hot & cold water in the flat Long answer: So definitions first, at 1:40 in the video, types of shower: power = has a pump, electric = water heated by electric. Is it just the feel of pressure that's the problem or a low flow rate? What flow rate are you getting? (take a 5 litre bucket, time how long to fill it. 60s = 5 litres per minute, 37s = 8lpm, 1m40s = 3lpm) If you have around 5 litres per minute now, then switching to an electric shower that uses mains cold water and heats it on demand would feel nicer and not need a pump (although this would not be my preference which is what this whole video is about). If you're getting more than 5 litres per minute now, then you could try changing the shower head to one with fewer holes. The same water flow rate coming out through fewer holes will feel stronger, like putting your thumb over the end of a garden hose to spray the water further. The pump for a power shower can be in the shower (not ideal, it's noisy) or somewhere else (typically the airing cupboard and pumping both hot and cold supply from the tank) but when specifying a pump we have to ensure the cold water storage tank is large enough that it is not likely to ever run dry during use with all the water pumped out of it. The pump as part of a shower (I think, I'd have to look it up and confirm) can be assumed to have a smaller cold water storage tank (as the pump is normally smaller and less powerful, so wont take quite as much water as the larger pumps that can be used to pressurise all the water in a home). I'd also caution you to be sure the pump is necessary. A pump will eventually fail (pumps work hard and don't last forever) and when they do that might mean your shower won't work until the pump is fixed. If you're getting more than 6 litres per minute now without a pump, it's worth trying different shower heads first. Steve

[@lakhpatd]

Amazing video. Can you make a video on toilets and the latest technology used in them

[@mikemcgibney]

Very useful and interesting! Thanks from Essex! Looking forward to replacing my 3 Ltr/min electric shower asap!

[@crouch.g]

Well done steve, my idea of a good shower is arround 7lth. We always need to be efficient with water, lower flow and shorter showers. We had conventional hot water tank in the uk and for larger family I'd go with that over combi any day only down side is you can run out of hot water in your tank. But that didn't happen often as long as kids showered early in the day, and I set the timer for a second hot water heat at 6 in the evening. Interesting australian build reg is whole bathroom tempering, all the water entering bathroom must be tempered to 50c so therostatic taps are rear, in fact plumber asked me what one was. Well done very thorough!

[@thecamdenstitch]

Hi Steve, thanks for this vid which was really helpful in explaining the limitations of electric showers. However you didnt specify in which circumstances an electric is the better option. I'm in an old house (lead pipes) with a gravity fed system. Cold water flow is 6l per min but hot is only 2. From the info ive given, what would you recommend? Thank you for your help, its appreciated 👍🏼🙏🏼

[@RootsKent]

Hi @thecamdenstitch2335, My opinion: best performance for a nice shower = if the cold water storage tank in the loft is big enough, pumped (the pump will pump both the cold water from the tank in the loft AND the hot water from the storage tank, which in turn is fed from the cold water tank). (also assuming you don't change to a mains pressure hot water system and remove the lot tank, which is they modern approach). 2nd best = Electric shower, the cold is supplied by the mains and NOT from the cold water storage tank. No pump = less to go wrong & the mains provides plenty of pressure. The low rate is low because of how quickly the electric element can heat water. You'll need a new electric wire from the shower to the consumer unit/trip switches. Bigger is better (10.5kw is better than 9kw, etc) 3rd best = Electric power shower, like the one at my Irish inlaws. There isn't enough water pressure from a lot tank for an electric shower alone, so this combines a pump and electric heating on just the cold supply from the loft tank. Flow rate is still limited by how quickly the electric can heat the water, and the pump is noisy. You'll have to check but loft tank size is less of a problem because the flow rate is lower than if you pump from stored hot water. Least expensive to fit and least expensive in running costs over time in most cases, though there are always exceptions and I could write an essay here ;-) = Electric shower footnotes: 6l per minute could be from the loft tank or mains if you're measuring a basin tap. As a rule of thumb, if you can hold back the water with your hand over the tap it's coming from the loft tank, if you can't hold it back it's coming from the water main. I hope that helps! Steve

[@thecamdenstitch]

@@RootsKent Thank you so much for your informative and helpful reply! I just realised I gave you the incorrect flow rates, the cold is 11l per min and hot is 5. But I think your advice probably holds good as there are no funds to change the heating system at present. Thanks again Steve.

[@RootsKent]

@@thecamdenstitch You're welcome, and 11lpm = mains for sure, so an electric shower (not pumped) will work well (providing you can get a suitable power supply to it). That said, 5lpm hot from gravity isn't bad either. A manual shower valve* (not pumped) will work just not with the feeling of force that mains or pumped has (5l hot + some cold to bring the temperature down from 55deg C to 40 deg C, = higher flow than an electric shower will provide.) Also in favour of a valve in this case; you're already heating the water in the tank so it's probably cheaper to use that than heat more water with electric (depending on the cost of heating the water in your tank, gas vs electric vs other methods). In Kent, we have a lot of hard water and limescale that slowly clogs pipes. If you have that, you might also investigate water softeners that use salt. These will dissolve the scale in the pipes over time and improve the flow rate in your current pipes. *make sure it's a model for low pressure!

[@thecamdenstitch]

@@RootsKent Thank you so much! I had looked at low pressure showers too, and I would prefer to use the water in the tank (as there's only two of us and we heat more than we need). You have been super helpful, thanks so much!

[@debs3657]

Thank you. Really helpful video! My house is off the gas grid which means I use electricity to heat and store hot water. I also have an electric shower. Would you recommend sticking with the electric shower or switching to a non-electric shower? I’m leaning towards sticking with an electric shower as I suspect it may be move cost effective.

[@RootsKent]

Interesting question, there are few variables to balance and the answer for you depends on those variables (sorry for the long answer!) For performance [in my definition of being good volume of water] (as this video describes), stored hot water + pressure (mains pressure or pump). For cost effective: a) If you have mains pressure stored water and have 'free' (or very low cost at a low rate) electric to heat water (solar/wind generator and the potential energy here isn't used elsewhere) then {stored hot water + no pump} b) If you have low pressure stored water and free/low cost electric, then the potentially the cost of a pump and it's running cost is less in the long term than electric only showers, so {stored hot water + pump}. c) If you have mains pressure water and regular price electric, then there's no advantage to slowly heating and storing water (as that uses more energy than instantly heating and using the water) so {Electric shower + no pump} d) If you have low pressure stored water and regular price electric, then as per C but you probably won't have good enough pressure to run the shower, so will need a 'power shower' electric shower, which is another way of saying an electric shower with pump. These are the noisy electric showers as the pump is in the shower with you. This is is the type of shower in the video from my Sister in laws home in Ireland. One advantage of storing the water is it's probably not going to be as cold as mains water coming into the house, so maybe the electric used to run the pump is offset by not having to do as much heating of water. So our final cost effective option is {Electric shower + pump} In your situation, I'm of the opinion cost effective = stick to the same type of electric shower Footnote on free/low cost electric - the down side of self generation from solar/wind is that often you don't have a high enough volume of electric on demand. EG: your shower may take 10.5kW but typical domestic solar panel arrays generated up to 4kW at their peak, never enough to heat water on demand. If you're not using that 4kW elsewhere though then slowly heating and storing water can be a good idea.

[@gdoldays9964]

Thank you for the very informative video 👍🏼 Just wondering if you can get a decent power (pump ☝🏼)shower via big LPG gas tank in garden?

[@RootsKent]

Sort of - it's not the source of heat that is important here, it's the pressure of the water supply.... long answer; If you have mains pressure water and heat the water on demand, an LPG gas boiler is normally good for 1 shower at a time (google phrases: combi boiler). If you have stored hot water, stored under mains pressure (google phrases: direct system, or 'megaflow' is a brand of mains pressure hot water tanks) then you don't need a pump. The water can be heated from any source (gas, oil, and electric) If you have stored hot water, stored without mains pressure (big cold water tank in the loft, insulated hot water tank often in the 'airing cupboard' in the UK, google phrase "gravity system") then your often(but always) want/need a pump ('power shower') to put pressure in the flow of that stored hot water. So, the question now is which is the cheapest/most reliable solution to buy/run and that depends on what you have, your home, long term plans, and more.

[@gdoldays9964]

@@RootsKent Thank you for the very detailed explanation! You've helped me allot to understand something that is very new to me 😅 Much appreciated 👍🏼

[@ROCKINGMAN]

Thanks for the info. Does a combi-boiler keep water hot like a flask? Example: A regular old boiler heats up water, say for an hour in the morning and what's in it get's colder in a day. Does a combi-boiler heat up say in the morning, and it will stay hot for the rest of the day, without further heating, like a flask?

[@RootsKent]

No, in the UK combination boiler (a.k.a combi boiler) heats water on demand. That means there is no heat wasted due to cooling but the amount of water that can be heated effectively is limited to how much gas you can burn. That's similar to the electric shower where the amount of water that can be heated is limited to how big an electric cable you can have, but unlike electric the gas supply is capable of heating a larger volume of water in the same time. Typically, combi boilers supply enough hot water for one bathroom (think shower or bath filling) at a time along with small amount of hot water used elsewhere (though you notice the flow rate of the shower changing if you have a thermostatic shower and someone fills the kitchen sink or runs the basin). The regular old boiler (all variations of these terms: boiler, system boiler or the words 'Direct', 'mains pressure', 'gravity') works by heating a store of water. It can even be less powerful than a combi but is effective because it can heat a store of water over a longer period of time. The store of water can also have multiple heat sources, eg: Gas and/or Solar Hot Water and/or Electric element. Hope that helps, Steve

[@ROCKINGMAN]

@@RootsKent Thankyou very much for this answer. Very valuable indeed.

[@billhughes9351]

HI Steve, We have a bath/shower mixer which flows at 1 litre/9.6 seconds. We are replacing the bath mixer with a thermostatic bar mixer. We are in a bungalow with a hot water tank heated by gas in the airing cupboard and a cold water tank in the loft. In your opinion do we need a power pump?

[@RootsKent]

>"cold water tank in the loft" == you have a gravity system >"1 litre/9.6 sec" = about 6 litres per minute so, for a thermostatic valve you'd need one that that works on very low pressure. Pressure = distance between shower head and bottom of cold tank, in a bungalow let's assume that's about 2m. For pressure, 1 bar = 10m height of water. You have 2m, so you have 0.2bar of pressure. I don't recall ever seeing a thermostatic valve that worked on less than 0.3bar. Note they'll all have graphs that show predicted flow at different pressures. Generally the higher the pressure the better but you have what you have. so the short answer is: Yes - it sounds like a power/pumped thermostatic shower == best performing in your situation BUT * a non thermostatic shower will be OK on the gravity system, probably what you have now (but not as safe, which is why we avoid them today) * a pumped shower may need a bigger water tank (more cost), a pumped shower needs a pump (more cost), pumps tend to go wrong from time to time (they work hard, but a potential point of failure and more cost) * an electric pumped shower (takes cold water from the storage tank) is an option (noisy as pump in shower area rather than in loft/airing cupboard), low flow rate but higher pressure helps with the feeling of shower, might cost less but might cost more with extra electrics needed, as in this video, potential it won't be as hot or have lower flow rate than you're used to now) * an electric non-pumped shower (takes water from the main, doesn't need a pump, does need extra electric work) is an option but probably at a lower flow rate than your current shower albeit the higher pressure means it will probably feel better. Like in this video, flow rate is probably less than you have now especially in winter, so it will more likely feel like a downgrade. Hope that helps! Steve

[@billhughes9351]

@@RootsKent Many thanks Steve I'm very impressed with you quick response especially on a bank holiday, I had been looking at a Stuart Turner Monsoon twin impeller 2.0 bar 46415 pump would this be suitable and what are your thoughts on this pump, pity you are in Kent and not West Sussex thanks again Bill

[@RootsKent]

​@@billhughes9351 Yes, that sounds right without checking details (eg: Is the loft tank big enough, what the shower valve needs, do you need positive head or negative head model, and more). You can call Stuart Turner advice line www.stuart-turner.co.uk/support/techassist. One alternative worth looking at are smart/digitial showers that include a built in pump. We use a lot of the Aqualisa models.

[@kaymurphy4636]

Which type of shower is more powerful, electric or thermo?

[@RootsKent]

Power as in feeling of pressure and amount of water delivered to your body? in order they are: 1.Thermostatic on mains pressure system (stored hot water tank) 2.Electric on mains pressure (heats the water as it passes through, flow limited by capacity of electric cable, so you feel pressure but at lower flow rates) 3.Electric Power shower (power means pumped from your cold water tank in the loft) 4.Thermostatic on gravity (fed from a cold water tank in the loft). Although there can be exceptions to this order. If your gravity water tank is very high above your shower, then you can get an effect equal to mains pressure. How high? 10 metres from bottom of tank to top of shower head = 1 bar of pressure. Think of a 4 story town house with basement shower... not very common. Water main is typically 3 to 5 bar, but sometimes less if you have small pipes in the home or old pipes are very small and impeding flow.

[@amjidali588]

I want a shower like Niagara falls

[@RootsKent]

OK, we can do that. A quick estimate: According to www.niagaraparks.com/visit-niagara-parks/plan-your-visit/niagara-falls-geology-facts-figures/ 168,000 cubic metres of water go over the crestline of the falls every minute. 1 cubic metre = 1,000 litres, so you're looking for a flow rate of 168,000,000 (168 million) litres per minute According to www.seatemperature.org/north-america/canada/niagara-falls.htm the water temperature varies between 1 degrees C and 23 degrees C Lets assume you like to shower at the EU Water label temperature of 42 degrees C, so I need to raise the temperature by 41 degrees C in the winter and 19 degrees C in the summer. Modifying the flow rate formula (see www.roots.uk/blog/2021/04/electric-showers-and-why-we-dont-recommend-them ) Flow rate = (14.3 * KW rating) / Temperature rise deg C becomes ( Flow rate X Temperature rise deg C )/14.3 = KW needed becomes (168,000,000 litres per minute x 41 degrees C)/14.3 = 481,678,321 KW and using the 10.8KW model electric showers you'll need 44,559,845 of those. *In round numbers, to have an electric shower like Niagara Falls you'll need just over 44 million electric showers in winter and just under 21 million electric showers in the summer.* You'll also need a suitable power supply for these but fortunately Niagara Fall has it's own Hydro Electric Power Plant en.wikipedia.org/wiki/Robert_Moses_Niagara_Power_Plant . Unfortunately it's 13 generators provide a design capacity of 2,525,000 KW which is a somewhat less than we need for instantaneously heating that volume of water. You'll need to build another 190 more of these power stations. The biggest problem with all of this is that Roots Kitchens Bedrooms Bathrooms only work in East Kent, UK so Niagara Falls is outside of our area of work. However, do pop in for a coffee as this sounds like an interesting project and maybe it's time I thought about expanding our small business. I hope that's useful, Steve Root

[@indeed596]

@@RootsKent One of the all time great KZbin replies! Spot on sir.

[@mehappym]

Hello, Thank you for this information. I have flat with two bathrooms , One en suite and one family . I would like to get rid of the hot water tank in my flat to use that space as storage . Is there a solution you could recommand. Is there a combi boiler that would provide enough hot water for both bathroom being used as same time?

[@RootsKent]

Unfortunately no simple solution to that scenario, because; > Is there a combi boiler that would provide enough hot water for both bathroom being used as same time? The answer is "Not that I've come across" (but if you find one, please post back to help others!) The issue is a combi boiler heats water on demand and for 2 showers running, say 20litres/m of hot water (or even 12litres/m) is a lot to ask. If you *know* that both showers won't be used at the same time (or both baths wont be filled at the same time), then you can argue it's an acceptable compromise to run 2 bathrooms on a single combi boiler and have the space in the cupboard. For most homes, both showers will be wanted at the same time - otherwise you'd also say have 1 shower and use the other shower area for storage. The next alternative is to use an electric shower in the less used room, which is what this video covers. Get the highest rated power (shower + circuit amps) you can for best performance. Even then you'll prefer your other shower but at least both will be functional at the same time. I guess lateral thinking would suggest having 2 combi boilers, but the expense would not be insignificant and I'm not sure at what point you'd need a dedicated gas supply to the 2nd boiler (I'd assume a combi boiler often uses the maximum supply of a gas to a domestic home but I'd research further to be sure). Also, I'm assuming the hot water tank in your flat is a mains pressure cylinder (as flat implies no loft for a header tank of a gravity system), so maybe there's a smaller model or differently shaped model that would allow you to improve your storage situation and keep the existing boiler. As I said in this video, for higher flow rates stored hot water is the only option and a mains pressure cylinder is the best option to achieve that. I hope that helps Steve

[@mehappym]

@@RootsKent Hello Steve, Thank you for your reply. Much appriciated. Thats right No loft for heder tank. Its an apartment . So if I use electic shower , can I keep one shower out of two on combi boiler water supply and the one with electric shower on cold water supply ? Would the flow of water still get affected if used at same time ? And how easy or difficult you recon it is interms of plubming work. am I looking at a huge cost ?

[@seismic6402]

@@mehappym Both would be running off the mains water supply effectively and the desired outcome may depend on the mains water pressure available. Running any outlet will affect the available water pressure at another outlet unless the water pressure is sufficiently high and pressure reducing valves are placed before both.

[@teresamartini10]

Help please! I wanted to install a Stiebel-Electron electric tankless water heater in my bathroom to feed the basin and the shower. I talked to their technical team and they told me I could have any shower with this unit. Yet when I was about to install it, the plumber told me it was not going to be good enough for a shower. I contacted Stiebel-Electron again, and they said that -running the unit at its max capacity- the best I'd get was 7 Liters per minute, which meant I could not have a shower that would demand more than that flow rate or I'd gate temperature fluctuations. The thing is that all showers on the market at a 2 bar pressure (which is what I have in my flat) deliver almost 20L/m. I'm very confused how Stiebel-Electron can then say their unit is suitable to feed a shower? Am I missing something? Shall I forget about this Stiebel-Electron unit and get an electric shower instead? Thank you very much!

[@RootsKent]

Hi T, I'm not familiar with Steibel-Electron but I just had a look at their web site and this seems pretty logical so far. They're instantons water heaters, so exactly the same as an electric shower but supply hot water into pipes instead of the shower head. Thus, you can also plumb them directly to a shower but also a hand basin or kitchen sink for doing the washing up. > they said that ... the best I'd get was 7 Liters per minute, OK, so that's very similar to the electric showers I described in this video. Depending on the model you have, but more importantly how much electric power that model can use, results in how much hot water flow you can have. Let's talk Flow and Physics first.: In the video (about 5m40s) I explained how water is heated by electric at a known rate, and thus we can calculate how much we raise the water temperature in degrees at a given flow rate. If the Stiebel-Electron can use 10.8kW of power, than it's going to perform identically to an electric shower. However, they have higher power options, including 3 phase electric version, so potentially they can add more heat to the water, or the same temperature but at a higher flow rate. Depending on your model, depends on the rate you get. >The thing is that all showers on the market at a 2 bar pressure (which is what I have in my flat) deliver almost 20L/m. I started the video by trying to define a "good shower" (2m58s). For me, I like 10 litres per minute but also found that 6 litres of water per minute was OK too. A higher flow rate is not necessarily a good thing, it will cost you more in water as well as the cost of heating that water. Environmentally everyone is being encouraged to use less water and showers are being pushed towards less than 6 litres of water per minute. Even though you may have the pressure and flow rate for 20l/m many showers will restrict the flow to a more budget and environmentally friendly flow rate. What I'm slowly getting to say is, 7 litres of water per minute should be OK. For sure a higher flow may be nice, but it will be acceptable. From the video you'll know that 7 litres (when adding 31.5 degrees of heat) isn't possible from a 10.8kW electric shower so I'm also assuming you're having a 3 phase/400v Stiebel-Electron? For temperature fluctuations I would assume (but don't rely on me!) you can still use a thermostatic shower valve (see start of video - introduction to shower types), so the temperature at the shower will be maintained even if the flow rises and falls with other uses of water (and I suspect there aren't that many other users of hot water if you've planned to use only instantaneous hot water. I'd assume it's a small apartment and you can avoid washing dishes in the sink if you partner is in the shower). Summary: I think the instantaneous heater might still be the best option for your home but I'm making assumptions when saying that. Hope that helps, Steve Feb - Aug 2022: Hi reader. If you're feeling generous, please consider donating a few pounds to my personal challenge to climb a mountain. All donations go directly to 3 chosen charities. More about why I'm doing this here: www.roots.uk/expedition-w3w and you can jump straight to the donation page here sponsorme.charitiestrust.org/event/cbdf1e64-4af4-4905-865d-49ebaedb105b

[@teresamartini10]

@@RootsKent Steve, what an amazing answer, thank you so very much! I was in a bit of a panic, but you've put my mind at peace. I'm fitting the Stiebel Eltron DCE-X 10/12 Premium with 12kw and 230V (don't have 3 phase at home). Based on your explanation, I think the unit might just perform as a very good electric shower, with its pros and cons. If in winter I have issues with the hot water flow, I might just buy a water saving shower head, to get more pressure with less water flow. I'll install it and report back in a few months on whether the unit does what it says on the tin!

[@RootsKent]

@@teresamartini10 > If in winter I have issues with the hot water flow, I might just buy a water saving shower head But if you get a thermostatic shower valve, the flow will adjust automatically 🙂 In this case a water saving shower head is like reducing the number of holes for the water to come out from, converting some flow into pressure like putting your finger over the end of a shower hose. A lot of showers will come with shower heads with variable spray patterns so you may find one of these already works well. At 12kW I think you'll be fine, that will perform better than a 10.8kW electric shower with regards to volume of water heated and thus flow rate, and you don't have the cost of having stored hot water! Sounds like a winner but do post back and share how well it works for you please, I'm curious now! Feb - Aug 2022: Hi reader. If you're feeling generous, please consider donating a few pounds to my personal challenge to climb a mountain. All donations go directly to 3 chosen charities. More about why I'm doing this here: www.roots.uk/expedition-w3w and you can jump straight to the donation page here sponsorme.charitiestrust.org/event/cbdf1e64-4af4-4905-865d-49ebaedb105b

[@unclek6197]

Hi I found this because I am in the same position looking to upgrade an old electric heated tank to Stiebel Eltron DCE-X 10/12. Did you go through with your installation? If so, are you happy with it? BTW I see that Steve recommended Thermomstatic shower valve but Stiebel advised against when I contacted them. The DCE-X model has its own technology to maintain steady temperature of the output water.

[@Sh4uN_b]

I have the the Aqualisa lumi 10.5kw electric shower, however the issue I'm having is when I turn the shower on the waters that's coming out is boiling hot no matter what temperature I set it as, and there is hardly no water pressure at the same time also, any ideas what this issue could be please?

[@RootsKent]

I'm on holiday with not enough internet to check, but I think the Lumi requires mains water pressure. "Hardly no water pressure" suggests you are connected to a gravity system (cold tank in the loft). If so, you could possibly solve by a) adding a pump, b) changing to a pumped electric shower (co-incidenally, that's what the shower in Ireland is that's at my lovely in-laws)

[@seismic6402]

Another solution may be to route a mains supply pipe to the shower. If you can do it for the kitchen tap, why not the shower?

[@RootsKent]

@@seismic6402 correct - Electric shower must have mains cold supply, whereas Electric Power Shower is fed from a water tank. In shower industry terms, "Power" is a synonym of "pumped".

[@kaymurphy4636]

I have a condenser boiler whereby I have a water header tank in the loft and a hot water storage cylinder in a cupboard in a bedroom. I have an electric shower at the moment so can just use it as and when I want to, but I am wanting a walk in shower ( thermal shower) , but will this cost more as I will need to heat up the water in advance probably a couple of times a day Thanks

[@RootsKent]

Yes, your running cost will be higher with a thermostatic shower than your current electric (which is true for most people, most of the time - see below) You've described a [Gravity, low pressure hot water system], it runs your central heating and I'm assuming because you have a hot water tank it provides hot water to the kitchen, basins and bath if you have one. You have an electric shower [water is heated as the water passes through] and I'll assume that's connected to the cold water main, which is high pressure Your electric shower is not a 'power' shower, because power in this context means pumped. You would have this if your electric shower was connected to the header tank in the loft. If you want a thermostatic shower [maintains a set temperature of water by changing the flow rate, if someone flushes a toilet or runs the hot tap on the kitchen sink]. There are a few that might work on your gravity system (pressures around 0.2 bar) but most require at least 1 bar of pressure and with a gravity system you'll need to add a pump (more cost) and sometimes a larger header tank (yet more cost). At some point, you might upgrade your system to a mains pressure (more cost) which is what you would do for a modern house today You can of course continue using an electric shower (no change in running cost) Purely thinking of cost, electric is often cheaper because as you say you don't need to heat the water up in advance AND they generally have lower flow rates so use less hot water. The exception is if you already run your hot water tank for having hot water to basins and sinks, because depending on how effective you are at turning that part on and off you may already be heating water and then not using it until it's heated again later. For performance, as I said in the video the low water flow rate of an electric shower is sometimes less than satisfying. Stored hot water under mains pressure will give a 'nicer' shower, albeit at a higher cost in water (you use more) and higher cost in energy to heat the water. The cost of the energy varies too, heating 50 litres of water through a gas boiler into a hot water tank costs less than heating 50 litres of water by an electric element. But if you have solar panels and you are selling sufficient excess back to the grid, then heating your tank by electric can be cheaper than gas. Likewise there are also systems that heat water during the day through solar energy - like a greenhouse of pipes on your roof, that reduce the cost associated with stored hot water. I hope that helps! Steve

[@declanjoyce8640]

Brill...

[@peterherring5274]

Would you be prepared to recommend a shower? Which model is the Equalise, featured in this video?

[@peterherring5274]

*Aqualisa

[@RootsKent]

Hi Peter, It's hard to recommend a shower without knowing a lot more about the room, the hot water supply, the client needs (eg: product durability, amount of flow and temperature control needed, if users may have difficulty in using certain controls due hand grip), plumbers experience and skills, and so on. The Aqualisa in the video that I have at home is an Aqualisa Q (there are several variants now, but note my shower head is not the normal one as I was experimenting with something else) and I chose the Q shower because our shower is over the bath. The Q control allows two outlets (handspray + overflow bath filler) and also allows settings to be saved, including how long it runs for and what temperature. That means we have a 'bath 1' set to fill the bath with a small amount of water for the childrens bath, and 'bath 2' for a lot more water and a hotter temperature for grown ups. We can set the bath to fill without watching it to set the level or temperature. I hope that helps, Steve

[@SharpestBulbs]

Why does UK have such an odd word for water heater? "Electric shower"? Sounds like you're going to get a shower head that shoots bolts of electricity down on you.

[@RootsKent]

😂I never thought of it that way. Is 'Water Heater' the US term? For us in the UK, we have 'hot water tanks' or 'hot water cylinder' for stored hot water which can then feed a shower (and basins, baths, etc), or 'electric shower' for when the water is heated instantaneously at the point of use. To confuse things further, we can heat the water in a tank/cylinder with an electric element which you can see at 7:19 . Electric heating of stored hot water is generally a backup to (the currently*) cheaper to run gas or oil boilers. *That's beginning to change as we move towards electric heating to combat climate change, using electric from renewables instead of burning fossil fuels in our homes.