🧀 Please tell me about Hot Water?

Morris_who_likes_Cheese

Hello ..

I’d like to find a better & cheaper solution for hot water on demand.

Could someone tell me what my options are. I think some sort of hot water on demand system but I have no idea what exists.

We have a house which was re-wired about 5 years ago.

Heating comes from storage heaters running on Economy 7

Hot Water comes from a large copper tank - which heats up overnight, but when I turn the tap on, it takes 20 seconds for hot water to appear. It’s not good.

The house has no bath - only a shower.

What will be the best / cheap(est) to run & install.

Is there anything else I should consider - grants, insulation etc. 

Thank you

M

neilmcl

Why do you need "instant" hot water, what's wrong with a slight, 20 sec delay for the hot water to come out.

Section62

Morris_who_likes_Cheese said:

I’d like to find a better & cheaper solution for hot water on demand.....

Hot Water comes from a large copper tank - which heats up overnight, but when I turn the tap on, it takes 20 seconds for hot water to appear. It’s not good.

How far is the tap(s) from where the hot water cylinder is?  Do you get a good rate of flow from those hot taps?


Gazing into a crystal ball of future domestic heating, anything heating hot water on demand is likely to become more expensive to use than your current arrangement.

You may be able to get better (in terms of hot water being more 'instant') but it is unlikely to work out cheaper overall.

coffeehound

Morris_who_likes_Cheese said:

What will be the best / cheap(est) to run & install.

Hi Morris.  Anything 'instant' will use expensive peak-rate electricity, plus you will obvs have the purchase and installation costs.  Agree neilmcl that a 20 second wait is not such a bad thing compared to that.  If your hot water tank and hot water pipes are not insulated, then that would be worth doing and will improve the situation

Morris_who_likes_Cheese

The taps are in the same room - the bathroom, where the rate of flow is very poor, so much slow, I could wash my hands twice by the time the hot water appears. 

More taps downstairs in the kitchen - rate of flow is better here.

My main concern is that we are heating up this giant tank of water - just to wash our hands a few times and clean a few plates. 

JJ_Egan

The guys and girls in the Energy board might have more information .

coffeehound

Morris_who_likes_Cheese said:

The taps are in the same room - the bathroom, where the rate of flow is very poor, so much slow, I could wash my hands twice by the time the hot water appears. 

It should be possible to reroute pipework to make the connection to the bathroom taps shorter there

Morris_who_likes_Cheese said:

My main concern is that we are heating up this giant tank of water - just to wash our hands a few times and clean a few plates. 

So your shower is not supplied from the hot water tank?

flashg67

Have a look at Fischer www.fischerfutureheat.com/electric-heaters/aquafficient/  
Overpriced IMHO, but ours works great.  I didn't like heating a full tank of water and hardly using it (I have an electric shower and only use hot water for washing up/occasional bath)
Yes, it has a similar 3kw heater (using day electricity rates for me as I don't have economy 7), but unless there's been a heavy demand, like a bath etc, the charging unit  hardly ever comes on (There's a charge indicator on the unit). Plus it freed up some bathroom space. The hot water is pretty much instant.
Sunamp offer a similar unit I think

Section62

Morris_who_likes_Cheese said:

The taps are in the same room - the bathroom, where the rate of flow is very poor, so much slow, I could wash my hands twice by the time the hot water appears. 

If the flow rate is poor at the bathroom tap, but better elsewhere, that points to the pipe between the hot water cylinder and the tap either being defective, or the flow being restricted by a partially closed valve.

A low flow rate means it will take longer for the hot water to reach the tap.

Trace the route of the pipe from the hot water cylinder to the tap - see if you can find any valves on it.

Morris_who_likes_Cheese said:

My main concern is that we are heating up this giant tank of water - just to wash our hands a few times and clean a few plates. 

If the cylinder is well insulated then the heat loss isn't as bad as some people will have you believe.

The more important point is how much you are paying for the electricity being used to heat the water.  If you can use ~half price electricity to heat the water overnight then you can afford to lose a fair bit of the heat and still break even compared to heating a smaller volume of water on demand using peak rate electricity.

Factor into your thinking that the roll out of smart metering will facilitate the introduction of time of use tariffs (similar to E7) and there is almost an inevitability that consumption at peak times (e.g. 7-9am and 4-7pm) will be charged at a rate sufficiently high to discourage use.  The ability to heat water off-peak and store it for use during the peaks would then become a very desirable feature.


However, if the only option available to me was the one flashg67 is putting forward then I'd give serious consideration to heating my water by burning £20 notes underneath a saucepan instead.

BUFF

Section62 said:

Morris_who_likes_Cheese said:

The taps are in the same room - the bathroom, where the rate of flow is very poor, so much slow, I could wash my hands twice by the time the hot water appears. 

If the flow rate is poor at the bathroom tap, but better elsewhere, that points to the pipe between the hot water cylinder and the tap either being defective, or the flow being restricted by a partially closed valve.

A low flow rate means it will take longer for the hot water to reach the tap.

Trace the route of the pipe from the hot water cylinder to the tap - see if you can find any valves on it.

Morris_who_likes_Cheese said:

My main concern is that we are heating up this giant tank of water - just to wash our hands a few times and clean a few plates. 

Or it's gravity fed & it's the difference in head between an upstairs bathroom & a downstairs kitchen.

Instantaneous electric handwash units exist e.g. https://www.toolstation.com/stiebel-eltron-hand-wash-unit/p69896 but even those will take a few seconds for you to get hot water plus you will have the cost of the unit & electrical installation. If it was me I think that I would put up with your current little inconvenience.

How is your shower water heated? Isit electric or does it draw from the hot water tank too?

Section62

Section62 said:

If the flow rate is poor at the bathroom tap, but better elsewhere, that points to the pipe between the hot water cylinder and the tap either being defective, or the flow being restricted by a partially closed valve.

Another possibility is the tap(s) in the bathroom aren't suitable for a gravity-fed system.  What kind do you you have Morris?