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Electric v power shower from cyclinder/combi?

chuffchuff
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Electric v power shower from cyclinder/combi?

Any difference in performance between a good electric shower over
a power shower coming off either a combi or a cyclinder (of hot water)?
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Re: Electric v power shower from cyclinder/combi?

An electric shower will usually be very close to the shower head and can deliver hot water quickly. A combi or cylinder is often a way away and needs running through if it is. I have found that electric showers tend to overshoot, even for an instant, and at first produce a slug of very hot water. You get used to it but it's not nice. Maybe I've just used gash showers? I personally prefer a non-electric because of this.
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Re: Electric v power shower from cyclinder/combi?

in my experience, electric showers tend to drop pressure the hotter the make the water.
this means that if you want a really hot shower you end up with poorer water pressure coming up the shower head.
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Re: Electric v power shower from cyclinder/combi?

the basis difference is that an electric shower is limited by the power of the heating element (flow x temperature rise) which usually means a lower flow than with the other types
Note that to fit an electric shower you would need to have a dedicated feed from your consumer unit and that won't be cheap as it will need a minimum of a 40 amp mcb
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Re: Electric v power shower from cyclinder/combi?

So could you have an electric power shower ?
By power shower I mean a shower that includes a motor to increase the flow of the water, I ask as based on the previous post which suggests a lower flow with an electric shower so would the power shower increase the water flow to the point where the heating element could not get the water hot enough ?
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Re: Electric v power shower from cyclinder/combi?

You would still have to have an arrangement which maintains the correct flow temperature by varying the water flow rate, so I can't see how a booster pump would be any use for a "normal" domestic electric shower. The flow controller would still operate and reduce the flow unless you wanted a cold shower.
I have a partial combi/cylinder which runs at mains pressure, and when the shower is running full tilt the boiler input is around 14kW gas equivalent. I don't know of any domestic pure electric showers of that capacity, but that would be the size you would need to get a very good mains-equivalent flow.
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Re: Electric v power shower from cyclinder/combi?

My domestic hot water is supplied using a condensing boiler downstairs and cylinder upstairs therefore I use an electric shower as I prefer to only heat the water I need for my shower.
My shower stops 4 seconds after I press the 'Stop' button as a safety measure. It flushes out the hot water so if I turn it straight back on I don't get scalded.
The shower has 2 power settings and I try to keep it on the low setting (what I call Summer setting) as long as possible.....very easy in this current climate.
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Re: Electric v power shower from cyclinder/combi?

Quote from: nozzer
I have a partial combi/cylinder which runs at mains pressure, and when the shower is running full tilt the boiler input is around 14kW gas equivalent. I don't know of any domestic pure electric showers of that capacity

An electric shower rated at 14kW would require a 60A supply, my incoming fuse at the electricity meter is 80A, wouldn't want to switch much else on at the same time as that was running.
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Re: Electric v power shower from cyclinder/combi?

2 or 3 years ago my 80 amp main fuse failed and the engineer who visited (very quickly) replaced it with a 100 amp fuse.
He said lots of main fuses fail due to age rather than overloading.
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Re: Electric v power shower from cyclinder/combi?

Quote from: Strat
fail due to age rather than overloading.

I know the feeling...

Quote from: Strat
2 or 3 years ago my 80 amp main fuse failed and the engineer who visited (very quickly) replaced it with a 100 amp fuse.

Oddly, when I had my meter changed a few years ago they changed the 100A fuse to an 80A one because they said the current  Cheesy regulations required the lower rated fuse for the size of my incoming cable.  Hope your cable's good for 100A.
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Re: Electric v power shower from cyclinder/combi?

The temperature of water from an electric shower is dependent on the flow rate and the power. Most electic showers are 9kW or less, so if you went for the highest rating your shower would be adequate, but never approach the flow rate from a power shower. The advantage is that the hot water is delivered close to the shower head.
A combi boiler is similar to an electric shower, in that it heats the water instantaneously but at a higher rating. However, if the boiler is a long way from the shower (in terms of the route that the pipework takes) then you could have to run the shower a while before hot water is delivered to the shower head. Combi boilers usually have a pressure reducing valve so whilst the cold water supply is at mains pressure the hot water coming out is not.
A power shower uses a pump to increase the flow of both hot and cold water, but is pretty pointless with either an electric shower or combi boiler as the faster the flow the lower the temperature. I don't believe that regulations will allow the use of a shower pump with either a combi or electric shower.
If you have a hot water cylinder then a power shower pump works well. I've not heard of combi boiler systems that include a hot water cylinder, but in theory it is possible if you want  to have different outlets fed either directly from the combi boiler or from the cylinder - this solves the problem of having say a combi boiler in a kitchen or utility room downstairs with a cylinder upstairs closer to the bathroom (or bathrooms if you have more than one) so you don't waste running water down the drain until hot water reaches the shower or bathroom taps.
You can get pressurised water cylinders (operating at about 2 - 3 bar) which would give a decent flow of hot water without needing a shower pump.
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Re: Electric v power shower from cyclinder/combi?

Quote from: maranello
I don't believe that regulations will allow the use of a shower pump with either a combi or electric shower.

You can get an electric shower with a built-in pump but I think they're only really useful for tank-fed / low head pressure cold feed systems.
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Re: Electric v power shower from cyclinder/combi?

Practical experience, we have run al electric shower for years at home although the heating is oil fired boiler  with a hot water cylinder. In the cottage we fitted a combi boiler and installed a sower with thermostatic mixer valve.
The cottage shower is a far superior shower experience with better flow and lashings of hot water. The electric shower OK but the combi boiler with mixer valve was a revelation  Smiley
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Re: Electric v power shower from cyclinder/combi?

http://www.amazon.co.uk/TMV2-Traditional-Exposed-Thermostatic-Bathroom/dp/B004X9S0O2/ref=sr_1_5?ie=U...
This is the style of valve we have don't go for one of those mamby pamby designer ones. More style than function  Cheesy
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Re: Electric v power shower from cyclinder/combi?

Quote
 I've not heard of combi boiler systems that include a hot water cylinder, but in theory it is possible if you want  to have different outlets fed either directly from the combi boiler or from the cylinder - this solves the problem of having say a combi boiler in a kitchen or utility room downstairs with a cylinder upstairs closer to the bathroom (or bathrooms if you have more than one) so you don't waste running water down the drain until hot water reaches the shower or bathroom taps.
 

I've got one. A Viessmann Vitodens 333. It's a beauty - combi with cylinder (ie partial combi).
Viessmann kit is streets ahead of the competition and being built in a cold country (Bavaria) they know how condensing equipment should work, as apart from the others who have strange ideas of how to wangle them to apparently get them to work.