Need advice on inline instantaneous water heaters

[snowcat]

Hi,

We are having our ancient gas boiler removed & I want to fit inline instantaneous water heaters in the upstairs bathroom (serving bath & basin - not simultaneously) & downstairs kitchen (serving sink & washing machine, again not simultaneously). I'm confused by the dizzying array of options! I liked the look of the DAFI 7.3 kW 230v (very cheap!), but am concerned that it will only heat to 40 degrees - this wouldn't be hot enough for a bath surely?

Do I need a higher kW to provide a reasonable temperature? What IS a reasonable temperature? Is it possible to fit 1 unit that would provide instant hot water to both? Also, can anybody give me a rough idea how much I would expect to pay a qualified person to fit? They all say installation is easy, but that each heater unit is to be wired to the Distribution Board via the existing Earth Leakage System - which really doesn't sound like something I should be attempting!

All advice gratefully received!

 

[solutions]

My knowledge of inline electric heaters is limited to electric showers. But if I were fitting a combi a 30kw would get you a 35 degree temperature rise on your incoming main temperature at a max flow rate of 12.4 litres a minute. How long do you want it to take to get a bath filled and at what temperature. In winter a 9.5 kw electric shower can at times struggle to provide a hot shower. Why do you want to fit electric inline? I cant think of a good reason.

 

[snowcat]

Basically I can't afford to buy let alone maintain a new boiler. Most of the ancient radiators don't work so we always use electric heating. So I need a way to heat the water without using gas & this is the cheapest way I can think of doing it as the units are less than £100 each. It would also get rid of the hot water tank & free up welcome space in our TINY bathroom. I rarely need to run a bath in a hurry, but I would like it to be hot!

I did wonder if it would be possible to convert the hot water tank into some kind of electric immersion water heater, but I have no idea if that is possible or what it would cost. I can't stress enough that cost & simplicity of the work is the driving factor here..!

 

[Ray Stafford]

Regardless of appliance you won't be able to make it work using domestic single phase power. You can just about get enough from the 11kw max that single phase will run to heat water fast enough for a slow running basin tap or a middling-poor shower, but it will never fill a bath faster than the water will go cold again.

Find somewhere to site a direct (electric only) unvented cylinder if possible.

 

[snowcat]

I have no idea what a direct (electric only) unvented cylinder is, but it sounds expensive! I have no choice than to have the boiler removed & no huge budget to replace it. Looks like I'll be boiling a kettle to do the washing up & just using the electric shower instead of the bath...

 

[Ray Stafford]

I have no idea what a direct (electric only) unvented cylinder is, but it sounds expensive! I have no choice than to have the boiler removed & no huge budget to replace it. Looks like I'll be boiling a kettle to do the washing up & just using the electric shower instead of the bath...

It depends on what you mean by expensive. Here is a smallish once from Screwfix.

But if there was a way to generate decent quantities of hot water at a reasonable price from an instantaneous electric heater - then everybody would be doing it.

Just as an aside, if I have baffled you by mentioning a direct unvented cylinder, then you either need to do loads more research, or get advice from someone who knows what they are talking about (other than an internet forum).

 

[SimonG]

Direct unvented cylinder is the way to go.

 

[snowcat]

Unfortunately £500 plus unknown labour costs is above my budget. I was looking for a cheap way to heat water without a boiler, but I guess there isn't one.

 

[solutions]

Unfortunately £500 plus unknown labour costs is above my budget. I was looking for a cheap way to heat water without a boiler, but I guess there isn't one.

Correct the only cheap way too heat water excluding initial install costs is solar or gas. No system is cheap once instalation materials and equipment is factored in. But then without it a house is little more than a cave. You would be better off putting up with your current situation untill you have saved enough for a better option, than spending any money on inline electrical water heaters that wont perform. Also I am not sure you appreciate the install costs of inline electrical units. The unit may appear comparitively inexpensive but with the cost of cable, new fuse way or alterations to your consumer unit and pipe work the cost will be alot more than you realise.

 

[SimonG]

Pans of water and candles?

Seriously though, post a picture of your hot water cylinder. It may be you have an immersion or one could be fitted.