Electric Boilers: Reliable and cost effective?

[SteamyTea]

1 minute ago, Nickfromwales said:

UFH and an ASHP really need to be designed in at the outset.

Well yes, but we are where we are, so short of pulling down all the hopelessly small places (a policy I am not against), we have to make places as useful as homes as possible.

Not that long ago, before the Sunamp was about, your general advice was to go for a combi gas boiler (if there was gas).

Just because there is a lack of imagination in the design of retrofit UFH, does not mean that it is totally unsuitable.

I am not claiming that a restively heated, wet UFH is the only, or compulsory heating solution, just that it should be researched seriously for a small home.

[Nickfromwales]

My replies relate to the OP  No gas.

A gas combi is deliciously simple and quick, and I'd still recommend one today if I thought it were the CORRECT decision. Cost / economy / running costs and practicality will be all the things the person PAYING for it will be asking about.

Design of retrofit is easy, and often free, just the design will need the property garnished with additional floor insulation / wall insulation / roof or attic insulation, and possibly upgrades to the windows and doors to meet the lower heat output per m2 that UFH can provide.

It is not a good choice for retrofit AFAIC, unless it is highly insulated and "energy efficient" in it's current state.

[Raks]

5 hours ago, PeterW said:

How big is the studio and how often will it be used ..?? 
 

Also, how well insulated is it ..?

 

I would go with a small under sink unit feeding kitchen sink and basin in the bathroom, and a decent 10kw electric shower.

 

For heating I would swap to a split air con unit that can do both heating and cooling, and an electric towel rail in the shower room to keep that warm. If you stay away from cold tiles and go with a vinyl/Lino type product for the bathroom too, then tile heating wouldn’t be required. 

Not very well insulated as it was an old bungolow, so no wall insulations but windows, floor and roof is ok. Quite small actually, its about 20 sqm. Probably the easy and less expensive way is one undersink (unvented), one electric shower (9-10 kw).  and a couple of electric radiators. (https://www.electricradiatorsdirect.co.uk/haverland-smart-wave-electric-radiators-anthracite/)

There is an multiport 11kw Storm Instant hotwater heater which can supply for sink and the shower hot water  but not sure if this is any better or reliable option then the first one.

https://www.toolstation.com/strom-11kw-touch-instantaneous-water-heater/p78066?utm_source=googleshopping&utm_medium=feed&utm_campaign=googleshoppingfeed&gclid=EAIaIQobChMIjeKD2bvd5QIVh63tCh1nhA60EAQYASABEgKZZPD_BwE

    

[Nickfromwales]

So as for an electrical design, you're already at ~20kW before sockets / lighting / kitchen etc  

Is this on it's own electricity supply?

[Raks]

4 hours ago, Nickfromwales said:

Fit a size 6 Uniq ( Sunamp ) and you'll only need a 3kW electric supply to get high pressure DHW on a 22mm supply   That will tee off to do basin / sink / shower from one source and no need for a discharge pipe and G3 annual inspection. Note: the Sunamp isn't a hot water tank it's an instant water heater / thermal store, so no actual 'stored water' to speak of. Next to no losses in comparison to an UVC, and a far, far more simplified installation with prob half the space or less taken up. It'll go into a kitchen unit as its only ~580mm deep x ~370mm wide x ~650mm high. Near zero maintenance too, as its only requires a single tiny expansion vessel that can be checked in minutes ( by anyone who's competent to do so ).

I will check that (sunamp) heaters. the uniq6 is 3.5 kw only and claims replace the 70l water tank, I just wonder if they can supply enough hot water for a shower (or at what temp and rate in winter)  I think this is the website: https://www.sunamp.com/

But I could'nt find any online price or seller yet.

 

[Raks]

9 minutes ago, Nickfromwales said:

So as for an electrical design, you're already at ~20kW before sockets / lighting / kitchen etc  

Is this on it's own electricity supply?

Will be rewired with a separate supply & meter 

[Nickfromwales]

8 minutes ago, Raks said:

I will check that (sunamp) heaters. the uniq6 is 3.5 kw only and claims replace the 70l water tank, I just wonder if they can supply enough hot water for a shower (or at what temp and rate in winter)  I think this is the website: https://www.sunamp.com/

But I could'nt find any online price or seller yet.

 

The 6 will suffice if it's given access to electricity on demand. I would go to a 9 if only if you have a bath. I fitted a 6 in Somerset and it's happily servicing a bathroom, kitchen sink, and utility sink in a household of 3 occupants.

 

8 minutes ago, Raks said:

Will be rewired with a separate supply & meter 

Great! No problem with adding an induction hob then ?

[Raks]

1 minute ago, Nickfromwales said:

The 6 will suffice if it's given access to electricity on demand. I would go to a 9 if only if you have a bath. I fitted a 6 in Somerset and it's happily servicing a bathroom, kitchen sink, and utility sink in a household of 3 occupants.

 

Great! No problem with adding an induction hob then ?

is fitting requires any special design or considerations?  should it be fitted only by the sunamp  engineer? any idea about the supply only  and with installation price of the models? 

[Nickfromwales]

Sunamp no longer deal with the public directly, so their products are only available now via re-sellers.

Sizing the unit size and type are quite specific requirements, so this would need to be surveyed by a SA accredited supplier. Installation price is "how long is a piece of string" as no two jobs are the same I'm afraid. 

[Raks]

3 minutes ago, Nickfromwales said:

Sunamp no longer deal with the public directly, so their products are only available now via re-sellers.

Sizing the unit size and type are quite specific requirements, so this would need to be surveyed by a SA accredited supplier. Installation price is "how long is a piece of string" as no two jobs are the same I'm afraid. 

I guess you are accredited but in Wales  I need one in SE London. Also I need some advice about "manifold for pluming  for water and central heating radiators as well as UFH.

[Temp]

1 hour ago, Raks said:

Not very well insulated as it was an old bungolow, so no wall insulations

 

Might be worth a look at grants. Mainly for people on benefits but perhaps your tenant might qualify...

 

https://www.government-grants.co.uk/free-insulation

 

You are likely to be eligible for 100% funding for insulation grants if you or anybody in your home are in receipt of one or more of the following benefits:

 

snip

 

The only limitation on the delivery of the scheme is that you must own the property to be treated or rent it privately and have the landlord’s permission to undertake the work.

 

If the walls are solid some councils have (had?) grants for "hard to insulate" properties, might be worth seeing if they have any money left.

 

 

 

[Ferdinand]

On 09/11/2019 at 17:37, Temp said:

 

Might be worth a look at grants. Mainly for people on benefits but perhaps your tenant might qualify...

 

https://www.government-grants.co.uk/free-insulation

 

 

 

If the walls are solid some councils have (had?) grants for "hard to insulate" properties, might be worth seeing if they have any money left.

 

 

 

 

If it is a conventional loft, then you should I think still be able to get free insulation.

 

Talk to the Energy Saving Trust for a local contact.

Suspect the Hard to Insulate stuff may be means tested.

Edited November 11, 2019 by Ferdinand