Instantaneous electric water heater - to fit or not to fit

[Bucklebean]

I currently have a broken gas fuelled hot water boiler in my flat, which needs replacing as the part (a circuit board) cannot be sourced apparently! All it does is heat water to the kitchen tap, situated directly below where the heater is on the wall, and the bathroom tap, some 30 metres away but on the same floor. I have considered a new gas boiler, but am thinking that an instantaneous electric water heater, fitted under the kitchen sink (or above, in the space left by the old boiler) might be a workable solution.
Can anyone tell me if this sounds like a good idea, and if so, what kind of water heater can anyone recommend.
I know the old boiler will need draining and the gas supply capping off, which i presume is something i have to get a corgi registered tradesperson to do. I am not sure if i am up to the plumbing/electrics side of fitting the new heater, so i asked a plumber for a quote.
Here's what they came up with for the whole job, including:
Drain down existing gas water heater, strip out and make good old flue hole. Supply and install Hot Flow electric 15L, Refill and test hot and cold pipework. Comes with 2 year guarantee.
£450 plus VAT.
Does this sound reasonable? I've seen electric heaters costing as little as £100, which would seem to do the job i need, so the £350 work bill seems steep. But is it?

 

[John506]

no because it could take a couple of days, sounds fair enough to me.

And yes you need a Corgi registerd gas installer to take out your old boiler.

 

[muggles]

Sounds good to me - bear in mind though that it'll cost you a lot more to heat the water using electric than it will using gas

 

[Corgigrouch]

I know that a cheap install price is probably very appealing at the moment, but do consider how much more expensive it is to heat water using an electric heating element over a little gas combi or multipoint water heater... You have to sit down and do the maths..

I note that you made mention of an instantaneous water heater... What you have seen will not heat your water instantaneously, it will give you 15 litres and then need to re heat... Consider how much energy you would need to feed in to an instantaneous water heater to get a decent water flow since most guys here regard 24kW as a bit limp for a gas fired water heater (Combi)

To do things correctly you will need a registered sparks for the electric heater too

 

[corgiman]

What boiler do you have at the mo

whats its name?

 

[Bucklebean]

What boiler do you have at the mo

whats its name?

Old boiler is a Britony Flexiflue, fitted about 6-7 years ago by previous home owners. Apparently the circuit board, which should make the burners fire up when the hot water tap is open, is knackered. The first guy who looked at it tried to find a part but it's an old bit of kit, and French, so no joy....or so I am told. Second set of plumbers didn't do much investigating, but agreed and suggested replacing the whole thing.
Maybe noone has looked hard enough yet so any suggestions of whether that part is obtainable are welcome! Gotta be cheaper than a total overhaul!

Regarding the issue that the electric option has high running costs - My bill for gas each month, which solely heated water for the two taps, was £5. Would using electric really add that much more on my electricity bill each month. Probably! When the gas boiler worked, I always had to run the water in the bathroom tap for a good few minutes to get it hot as the pipes go through the loft space, where it is arctic!

 

[big-all]

Regarding the issue that the electric option has high running costs - My bill for gas each month, which solely heated water for the two taps, was £5. Would using electric really add that much more on my electricity bill each month. Probably! When the gas boiler worked, I always had to run the water in the bathroom tap for a good few minutes to get it hot as the pipes go through the loft space, where it is arctic!

look at your bills to find out !!!

typical 1kw gas 4.5p typical 1kw off electric 11p
so with 20% waste on the gas its still half the price
and if your electric heater maintaines 15L at around 80 degrees i would imagine you could triple your leccy consumtion over gas at £15 a month or an extra £120 a year!!!!!

 

[pmx_super]

I installed one of these under my sink:

http://www.aquahot.co.uk/index.php?action=store&id_prd=639

The red light on the front comes on when the element is on. I reckon it's lit for about 30 mins per day tops (except the day the cleaning lady comes - maybe an extra 30 mins then). At 11p/kWh that's about £4 per month.

Having a dishwasher I don't find the hot tap in the kitchen gets used that much. Once you've exhausted the 15 litres stored it gets hot again in about 5-10 mins.

Oh, and £450 sounds cheap. I was quoted that for a like-for-like replacement of my old electric heater, before deciding to Do It Myself.

 

[JohnD]

that electric heater will give you one and a half bucketfuls of hot water (much less at the bathroom as it has to fill 30m of pipe before any gets to the tap) and then it will run cold

presumably you just want to wash your hands, and don't want a bath or shower

it is more or less impossible to deliver hot water from an electric heater at the same rate that a gas heater can deliver it.

Even a 45Amp electric shower delivers at a rate of half or a third what a gas boiler can, and you woud fall asleep waiting for it to fill a bath (needs about 100 litres).