These are cash grants not deductions (as they should be! They are covering a one-time cost!)
This is for single family detached homes (which are almost invariably owned)
A boiler makes hot water in a tank in the basement and showers, radiators and taps use that hot water?
I have seen (In Scotland) some extremely weird contraptions where water was heated in the shower by what I can only assume was an flame in a box on the wall. But surely that’s not what Germans and others on the continent are using? They do have a central hot water system?
How else is water coming to the radiators? I guess my question is: are there gas lines around a typical home to any other place than the boiler and possibly stove? Why?
The gas boiler can directly heat up cold water and provide sufficient flow for a hot shower, but the heat pump cannot. Because of this you need to buffer the heat in a hot water tank, usually something that's a few hundred litres, and heat it up over time. I believe boilers using heating oil work somewhat sim
In the UK houses heated with gas usually don't have a hot water tank, or even anywhere to put it. You can get all-in-one heat pump units that are the size of a large fridge which have a built in tank, but I've lived in places where there wouldn't even be space for that.
The boxes in the showers used in the UK are electric. They work pretty well (esp. considering most homes in the UK are single phase), but I am always concerned by the fact that an electric wire carrying 30kW of power is running right next to running water :-) Other than a gas boiler older homes may have a gas fireplace, but they are not so popular now.
There's also issues of the flow temperature for the heating system. Traditional central heating usually has a temperature of 70-80C, where as underfloor heating systems using a heat pump usually have a max of 35C. With a heat pump the efficiency drops with the temperature delta, so they are optimised to produce lower temperature water. But traditional radiators work better with higher temperatures.
It also connected directly to 4 pipes hot/cold tap and hot/cold radiator water making an easy swap.
Are you saying the space requirement of 60x60x180cm would really be the problem?
When you talk rent in London the first question asked tends to be "bills included?". This suggests to me that a non-trivial number of landlords would be interested in efficiency. Anecdotal, I don't have the data for the whole UK.
In my entire life I have only seen bills included in properties that were rented room by room, i.e. each room has a different tenant. I have never seen that for entire property rented to a single tenant
is this something new? i have been renting in London for almost a decade and I have never heard of a landlord or agency offer to pay my bills.
Conversely, poorest people rent the shittiest and least efficient homes, but they don't have the choice to replace the heating system - that's the landlorsa decision. But he doen't pay the utilities, the tenants do, so why would he care?