Energy Upgrading for Shower Problems
 

We recently bought a new house and because we are in our 70's we cannot carry butane gas bottles on the flight of stairs to our kitchen so had an electric boiler which has been in for one month. We have also bought a Grohe Thermostatically Controlled Shower Bar for the shower but we are having problems keeping the water hot whilst in the shower, abougt 3 min is the maximum before it starts running cold, I barely have time to wash my conditioner off my hair and it is cold when I am doing it. Our plumber told us to turn up the boiler temperature so we did to 55c (the boiler is an 80L - supposedly sufficient for 2 good showers) but when you get in it is too hot at 55c and after a minute you get in and it is running cold after about 3 minutes which is most frustrating (I tried using it with the thermostat set at the standard 38c and it wasn't hot enough for me so we turned the valve up to 45c which made no difference to the length of time it stayed hot. After some research I have found out that the boiler can only supply approx. 6-8L of water a minute for a good shower, whilst the Grohe shower bar delivers 21L per minute and the shower head itself delivers 3 bar / 14L per minute.

Something is not quite right as some people have told me they have a good 10 min shower out of an 80L electric boiler but the boiler is only 2Kw power and I believe that we need a higher performance boiler to produce a couple of decently hot showers for more than 3 minutes.

Any plumbers out there that can advise us what to do ?

Re: Energy Upgrading for Shower Problems
 

We have a standard type 80 ltr electric water heater. We also have a standard type shower operating from the boiler. I have the boiler on a timer so that it heats up overnight on low rate electric and also again late afternoon when it's mid rate electric. That is sufficient to provide hot water for showering and general use throughout the day, it is very rare that we need to heat the boiler in-between the times I have set on the timer. We certainly get our full showers out of that without any issues. What temperature our boiler is set at I don't know , I know it gives out very hot water on full hot but we adjust that from the shower or tap controls to suit what we need. Is your shower on a pressure pump ? Ours is simply mains pressure which provides a more than adequate shower pressure. Clearly something isn't working with your set up if it's using 80 LTRs of hot water within a few minutes.

Re: Energy Upgrading for Shower Problems
 

Our boiler doesn't even have a programmer on it. The plumber we asked to put in the boiler didn't seem to think we needed it 🙄 It is mains fed with no pump attached to it. He said to keep it on 45c and it would be plenty hot enough. When we complained of the shower not being hot enough, he came and took off the end of the shower bar and moved the thermostatic valve so it would get to 45c and then turned on the water on the shower and asked me if it was hot enough. I put my hand in it and it was luke warm and I said "No Way" ! I like my showers hot and he just suggested turning up the thermostat on the boiler to about 55c. We did that and when we went to use it the next time we waited for the hot water to come through, about half a minute and it was boiling hot so of course I couldn't get in it, waited about 1/2 a minute for it to cool down enough, got in and as I was it lasted about 3 minutes, I had just put the hair conditioner on my hair and mixed it in, came to wash it off and the water was stone cold ! If our shower head is pulling through a shower flow rate of 14L from the boiler, surely it is not going to stay hot for long is it ? By the way is your electric boiler in your bathroom? Ours is on the floor above and I wonder if that makes a difference with how far it has to travel to the shower head 🙄

Re: Energy Upgrading for Shower Problems
 

I wonder if the issue is that the water pressure is to low and the plumber may also be an issue.
BTW Grohe is a good brand in my experience

Re: Energy Upgrading for Shower Problems
 

Our boiler isn't in the bathroom it's in our bedroom which is on the same level as the bathroom. Our shower is just a standard shower head from a basic shower mixer tap to adjust temperature mixing cold with hot. It works fine and gives a good shower. Our shower tap isn't thermostatic so that may be the difference.

Re: Energy Upgrading for Shower Problems
 

Grohe is a good brand that we also had in the UK but that operated from a Combi boiler which obviously keeps the temperature constant. I don't rate the plumber as he doesn't seem to understand how flow rates affect the performance so I did look it up online about the flow rate . So presumably from what it says a 14Lt shower head rate from a boiler which can only handle between 6-8L a minute is going to cause the temperature to drop dramatically in a short space of time because it can't heat the water coming into the boiler quickly enough for the rate it is flowing out! Looks like I might need a shower head with a lower flow rate !🙄

Re: Energy Upgrading for Shower Problems
 

You are describing an "instant" water heater, but you say you have an 80-litre water tank with an immersion heater. I have used these for years with a high-pressure pump and never had a problem. I suspect the thermostatic shower control. Try changing it for a basic shower mixer tap.

Re: Energy Upgrading for Shower Problems
 

It is an electric boiler, not an immersion heater, it holds 80L of water, we bought it here in Spain, it does not have a pump. It's not "instant" if it takes it about 40 mins from cold to heat a tank of water. Our problem is as soon as you get in the shower and turn it on, it has a long way to come from the boiler and takes a minute or two to get hot and then it only lasts about 3 minutes but then as I say, if the shower head is delivering 14L of water a minute and the boiler holds 80L and the cold water is running into the boiler within half a minute or so, it only takes about 4 minutes from when you turn it on to empty the boiler of hot water and it is running almost cold. I think it must be the shower head but I am open to advice from a professional.

Re: Energy Upgrading for Shower Problems
 

From what you describe it sounds more or less the same set up that I have although I do not have a thermostatic shower control. It is in fact really just an 80 ltr capacity immersion heater . Ours takes a little while to get hot water first thing as the length of run from the bedroom to bathroom. As Fred says I would suspect the issue may be the thermostatic shower control. obviously you only have 80 LTRs of hot water but when you mix that with cold via the standard shower control tap you get more than 80 LTRs of water to shower with. You want the water in the heater to be hotter than temperature you shower with and using standard mixer get it to the right temperature mixing with separate cold water input, thereby extending amount of water at suitable temperature to shower. Like Fred that's the system we have used for last 18 years without issue. Only issue we had when we first bought the house was that the water was from the mains fed deposito and pressure was near zero in bathroom so I added a bit of pipework so that we get near mains pressure to feed the shower taps etc in the house and also fill deposito for emergency use for any mains cut offs. Is your water boiler on all the time heating the water ? Mine doesn't have an internal timer but I fitted a simple timer to it which works well.

Re: Energy Upgrading for Shower Problems
 

Yes it is on all the time. I would like to fit a timer to it it though if we could. I asked the plumber when he put it in if it had a timer programmer on it and he said no, you don't need one, just keep it on 45c all the time and it should be OK. 🙄

Re: Energy Upgrading for Shower Problems
 

IThat sounds quite a low setting but I am no expert . My temp control isn't in specific temperature I just have it on quite high and that allows us to mix it with cold via shower and tap mixers .

Re: Energy Upgrading for Shower Problems
 

Yes there are so many different variations in both electric boilers and showers, it is difficult to know what goes with what these days and I am a technophobe when it comes to the intracacies of putting these components together that match !🙄

Re: Energy Upgrading for Shower Problems
 

Of course it’s an immersion heater, how else do you think it heats up. It’s a tank of water with a heating element in it. That’s an immersion heater. It’s a heater immersed in water hence the name. Just change the shower thermostatic mixer and see if that fixes it. And find a decent plumber!

Re: Energy Upgrading for Shower Problems
 

I believe Spanish electric boilers have TWO tanks with an isolated heating element 😉 We don't have a mixer shower bar, we have a thermostatically controlled bar which cost us 160 euros just a month ago 🙄 If we can find a cheaper alternative to changing that, then that will suit us !

Re: Energy Upgrading for Shower Problems
 

Of course it's a mixer tap, as it is connected to both hot and cold water supplies. The thermostat in the mixer controls the amount of hot and cold water. Just Google it if you can't understand such a simple bit of technology, or, as I said earlier, find a decent plumber.

Re: Energy Upgrading for Shower Problems
 

No, they don't. They have one simple insulated tank with a heating element inside a tube that is immersed in the water. As the element is usually inserted from the bottom of the tank, it can easily be replaced without draining the tank. Why would it have two separate tanks?

Re: Energy Upgrading for Shower Problems
 

That is what I read in the technical blurb that accompanied the boiler !

Re: Energy Upgrading for Shower Problems
 

Cheap low tech solution to try: add a water restrictor between the between the shower head and hose? Might not fix the problem completely, but showers could last for longer.

Re: Energy Upgrading for Shower Problems
 

I was reading about them but I also read that all shower heads are already supposed to have them 🤔

Re: Energy Upgrading for Shower Problems
 

Could it be that as you like your shower quite hot and the boiler temperature to me doesn't seem that hot ,that the the thermostatic mixer you have is sensing the water doesn't need mixing with cold water. Therefore it simply running straight on hot water using your tank capacity quickly? I would try putting boiler temperature much higher that way the thermostatic mixer will adjust temperature of water coming out by mixing and increase amounts of hot water you have available. That may resolve the issue certainly worth trying before going to more expense?

Re: Energy Upgrading for Shower Problems
 

Couldn't say but at 14L/min it wouldn't hurt to try. Ours is fitted with them and it makes a difference.

Re: Energy Upgrading for Shower Problems
 

Good idea, I know what you are saying which makes sense but we would get scalded when the hot water eventually came through if say we increased it to say 65c, as when it first comes through it is too hot to stand in and you have to wait about half a minute for it to cool down, which makes me wonder whether the thermostat is working correctly. The valve was adjusted to allow the water to come through up to 45c, is that scalding temperature because it is too hot to stand in when it first comes through.

Re: Energy Upgrading for Shower Problems
 

I think I need to ask a plumber if it is fitted with one. Or maybe it mentioned it in the sales blurb, I will have to take a look.

Re: Energy Upgrading for Shower Problems
 

If the issue is that you have very high water pressure which is pushing out all the hot water from the tank quickly why not just reduce that amount at the shower bar? Don't have it on full. When I converted our water to increase pressure as it was feeding into the deposito from mains and then feeding the house water from the deposito by gravity , the standard way most older Spanish properties work. I was advised by someone who was a plumber in the UK how to add a few pipes so that the mains fed direct to both the deposito and household water supply. He said the mains pressure would be too high and to put a water pressure reduction valve in the system more or less where the mains entered the house. I did that and all was fine until around 18 months ago when our household pressure reduced significantly. I thought it must be to do with actual supply maybe reducing pressure to conserve water as measures were being taken to conserve water in our area. It got really bad so we got on to the ayuntamiento who said town plumber out he dug up our pipes etc and said he had found no significant problem changed a few connections etc but no real difference. II then thought mmmm could it be the pressure reduction valve which I pointed out to the plumber. So he checked pressure before the valve and after and yes that was the issue. He asked me why I had it on as I didn't need it? He said if water pressure was too high just don't open the stop tap fully. I removed the water pressure reducing valve which had in fact simply calked up , I then opened stop tap to give sufficient water pressure to house taps and all has been fine since. In fact even now for the shower we don't have the shower control fully open as it's then like a power shower and would just waste our hot water, we just open it sufficient to give us a good shower without any issues and making our limited hot water last longer.

Re: Energy Upgrading for Shower Problems
 

Re: Energy Upgrading for Shower Problems
 

I thought about that too and am going to try that tonight and will report back. The only problem I may encounter is that the shower head is at a fixed height and not adjustable down if the flow is restricted. Hubby will be OK, he is at least 6" taller than me 😁 I will let you know how I got on ! May have to turn the temperature down at the valve inside though as that will obviously increase the temperature and it is already set at 45c.

Re: Energy Upgrading for Shower Problems
 

Too things can you not reduce the output using the shower bar control ? It's a tap surely you have one control for heat and one control for output pressure just like a tap? If not then why not just use a simple standard manual shower mixer tap that allows that. I honestly think you have the water temperature for boiler too low so it is not mixing hot with cold water to give desired temperature. That is how one would have it set up for an instant water heater such as a combi boiler in the UK but not for a simple immersion heater with 80 litre tank. It's like orange squash you dilute the squash with water to suit taste more it's diluted longer the bottle of squash lasts

Re: Energy Upgrading for Shower Problems
 

Average. Shower temperature is around high 30s to mid 40s centigrade so you are running your boiler at average temperature to shower ? That would be fine with an instant heating system such as combi boiler but you only have 80 LTRs of hot water. If that hot water is much more than the heat you want to shower at the boiler then the thermostat at tap will introduce cold water possibly doubling the time you can draw hot water. As I say turn the boiler temperature right up to see how that works and adjust shower bar for both heat and pressure to suit both yourself and your husband , that's exactly how we do it my wife is 5ft 7 I am 6ft 2 so we adjust shower head to suit without issue.

Re: Energy Upgrading for Shower Problems
 

We set the boiler to 55c but as I say it is too hot when you first get in but after half a minute it cools down, that is how fast the temperature drops at the boiler😮 To compensate we either have to wait for it to cool down and then you have about 3-3.5 mins to shower before it runs cold, or else reduce the temperature at the valve down to less than 45c which it is set on. Our shower head is at a fixed height so non-adjustable.

Re: Energy Upgrading for Shower Problems
 

Try reducing temperature at shower head and increase it while showering if starts to cool. You are wasting hot water by letting it run too hot until it cools to suitable temperature. I get that you cant adjust shower head height but you must be able to adjust pressure of output. If you are having at high pressure such as you would get with a power shower im afraid 80 ltrs of hot water will not last too long. The hotter the water is in the tank maybe over 55 Deg then the more you can reduce shower temperature by mixing cold which in your case is done automatically with thermostat. You may have to accept slightly lower power from the shower but get longer with hot water. Its probably a compromise such as that or a different system or larger capacity boiler .

Re: Energy Upgrading for Shower Problems
 

Your shower bar must be similar to this in photo?
The knob on left of shower bar reduces or increases pressure by rotating . The Knob on the right reduces or increases temperature of water from shower. The thermostat built in maintains that tenprature you choose so long as there is hot and cold suoply

Re: Energy Upgrading for Shower Problems
 

I'm confused...

You say that your plumber etc said to increase the temp of the heater to 55c.
We have a fixed setting one and it gives water at 65c.

Does your shower not have a mixer tap???
Nobody in their right mind would only run a hot feed to a showerhead.
I like coldish showers and the wife likes to steam up her bathroom.
All we do in our respective bathrooms is move the mixer to the desired spot.
Depending how far from the heater you are, there will be a waiting time for the full heat to come through (my bathroom is the furthest from the heater)

We can do the washing up a couple of times a day, each of us shower and there is still lots of hot water left from one heat cycle.

Re: Energy Upgrading for Shower Problems
 

yes that is identical to us I think OP has the mixer bar set up which will have an output pressure control andan heat control.That is point i am trying to make 80 litres of water will not last long if that is all you are using for your shower. You must have the hot water (hotter than 45 deg ?) and mix it via mixer bar to desired temperature and shower pressure. At the end of the day the shower bar is just a fancy tap combining hot and cold water.

Re: Energy Upgrading for Shower Problems
 

Yes that is how the shower bar is designed, water pressure on the left and temperature control on the right. What photo?

Re: Energy Upgrading for Shower Problems
 

We have a temperature knob on the electric boiler which goes to 75c but I have read that the more you turn the boiler to maximum, the quicker it will deteriorate so the plumber told us to keep it at 45c but to shower I turned it up to 55c because it is not hot enough. The shower bar itself is a Grohe Grohtherm 800 thermostatically controlled device, it obviously mixes the cold and hot but controls it thermostatically but ours is not controlling it because the water is coming from the boiler which is emptying fast and the temperature at the boiler drops fast with the cold water coming in so our showers soon run cold as the shower head is delivering 14Ltrs of water a minute, so as suggested I am going to try turning down the water pressure on the shower bar and see if that helps. I have heard from other plumbers that these type of shower bars do not work effecively in Spain off an electric boiler but when I questioned Grohe on this they said they did !!! Go figure !

Re: Energy Upgrading for Shower Problems
 

Yes you are probably right, we probably should have just bought a straight forward mixer tap for 20 euros instead of paying 160 euros for a shower bar which is not able to do its job effectively off an electric boiler, but as usual our plumber never advised us what to do and we have always had a combi boiler with a consistent temperature output and controlled the temperative and water flow in the shower and it remained constant !😞

Re: Energy Upgrading for Shower Problems
 

I think your thermostatic shower bar will work fine,. I would just try turning the temperature of the boiler up high and adjust the heat and shower pressure from the shower bar. I guess all will be fine if you do that as you will be putting hot enough water through the bar so it can efficiently give you the correct output. You can't use it as you are used to like you did in the UK with the combi boiler. You just need to familiarise yourself to your new set up I'm afraid. Good luck and let us know how you get on .

Re: Energy Upgrading for Shower Problems
 

I would say that the shower bar is not doing its job because the hot water entering it is not allowing the thermo valve to open to let cold water in to balance the system.
Either the bar is faulty or you don't have it set right.

Knock on wood our water heater is 20 years old and has been in almost daily use for six years now (previously it was only used for a month or so a year).
So setting it higher has not affected it yet.

Re: Energy Upgrading for Shower Problems
 

Something is very wrong here.

You say the boiler is 2kW, which is actually on the high side for Spain where 1.5kW is more common, but then say that it heats 80lt of water in 40 minutes which is a physically impossibility.

Assuming an efficiency of 95% and a start temperature of say 25c to heat 80lt of water to 55c would require 2.8kWh of electricity which, with a 2kw element, equates to about 1.5 hours NOT 40 minutes!

You therefore need to need to put the heater on for at least 1.5 hours to get a tankful of 55c water.

The flow rate is a factor of the available water pressure not the boiler.

BTW 45c is too low, 55c is the recommended temperature to prevent Legionella.

https://www.greenbuildingadvisor.com...naires-disease

Re: Energy Upgrading for Shower Problems
 

Touch wood, let's hope ours in the same !🤞