Electric shower from the hot water tank?

[Madrab]

When you get down to the basics of this .... if you are running out of hot water then firstly you need to look at what size (how many litres) of HW cylinder you have. Then how long each shower taken is and then how the HW in the cylinder is replenished by whatever heating system you have.

Presuming you have a gas/oil boiler that heats the hot water then all you really need to do is shower smarter ... one person has a shower, then with the CH system on HW, wait a period for the HW to be replenished by the system (this is determined by size of cylinder/internal heating coil and specified recover time) then take the other shower.

Don't just throw a standard/pumped electric shower at it as you will probably be really disappointed by it's performance compared to what you have.

 

[baggie79]

Thanks for the replies.

How does an electric shower that takes a feed from the tank in the loft compare to one that is cold water mains fed? Is the performance the same or better than the mains-fed electric shower?

 

[Johntheo5]

Its exactly the same, a 9kw tank fed shower will consume a tiny bit more power, ~ 100/120 watts to power the pump.

 

[Harry Bloomfield]

Thanks for the replies.

How does an electric shower that takes a feed from the tank in the loft compare to one that is cold water mains fed? Is the performance the same or better than the mains-fed electric shower?

As above, it will be the same problem of a limited amount of water, able to be heated by a 9Kw heater, plus the additional cost of running the pump. Advantage gained nil.

I suspect your present 'electric shower' is in fact a pump only, in the box - no heating element. I'm surprised your boiler is not able to replenish the hot water in your cylinder quick enough, perhaps restrict the time each spends in the shower?

I'm one of the strange people who finds electric shower supplied direct from the CW main perfectly adequate for the purpose of taking a shower.

 

[Johntheo5]

I have a 9kw electric shower + a gravity fed shower fed one from the HW cylinder, the gravity fed gives about 8LPM.
A 9kw electric shower will give 3.79LPM in winter assuming a lowest cold temperature of 6C and 5.16LPM in summer assuming cold water at 15C.
The equivalent numbers for a 9.5kw/10.0kw/10.5kw are 4.00/5.45LPM, 4.22/5.73LPM & 4.43/6.02LPM.

 

[JonathanM]

I wonder whether another way might be to spend the money on a new hot water cylinder which meets your needs, in terms of capacity and how fast it heats up, rather than on the electric shower. Is that a mad idea?

 

[baggie79]

Great replies guys, many thanks. I think I'm best off going with a direct replacement for the shower I had (pumped). Seems the safest bet. Ideally, i'd replace the boiller and put a combi in there but thats £££.