Originally Posted by Mad Max (Post 36139513)

Your boiler is past it's sell-by date, it's probably costing you money, I know they're pretty expensive to get a new one, but, if you can afford it you will save in the long run.

Originally Posted by Mad Max (Post 36139513)

Your boiler is past it's sell-by date, it's probably costing you money, I know they're pretty expensive to get a new one, but, if you can afford it you will save in the long run.

Originally Posted by Taf (Post 36139520)

The new regs demand boilers run radiators at 50c. For this to work, you may have to have ALL your radiators and pipework upgraded.

That won't be cheap. Our local council is replacing end-of-life condensing combi boilers with the new standard, and are warning tenants that "installation will be very disruptive in most rooms of your home".

Originally Posted by nomadking (Post 36139522)

With radiators having to be 3 times the size, heat pump systems are not going to be great.

Originally Posted by Chris (Post 36139526)

If you need to triple the size of your radiators for a heat pump installation, then your radiators are inadequate even with a gas boiler. They’re probably very old, not at all efficient and ought to be replaced anyway.

Worst case in a UK home is likely to be a 2.5x increase, but don’t forget that in many cases that can be achieved by using double or triple panelled radiators with convector fins.

Originally Posted by nomadking (Post 36139527)

With a heat pump system, the radiators operate at a much lower temp. The tank of water used is lukewarm at best.

Originally Posted by 1andrew1 (Post 36139528)

I just want a decent electric boiler that I can just swap over for my gas boiler and everything else stays as is. Not sure how far off we're at getting something like that?

Originally Posted by Chris (Post 36139529)

Heat pumps operate better at lower output temperatures. The best balance between temperature and practical radiator size is 50*c. This, as it happens, is the same temperature the latest regulations require gas boilers to be operable at. 50*c is also definitely not lukewarm and is easily hot enough to burn your hands. 50*c is more or less what you’d want coming out of the hot tap in your kitchen.

So if you’re getting a new gas boiler and it’s running at 50*c you’re going to have to match the radiators in the house to the new, lower operating temperature. And that’s the same operating temperature as a heat pump.

All this ‘yeah but no but heat pumps don’t work’ is nonsense anyway. Heat pump usage in Europe is highest in some of the coldest places, including Norway where 60% of homes have one. Heat pumps absolutely do work, they do however require an attitude that heat energy should be conserved, rather than carelessly leaked out of the walls.

The British problem is that we burned coal in our homes for two centuries, and that coal was so cheap we never really had to think about keeping the heat in.

Originally Posted by nomadking (Post 36139539)

Link

37°C is body temperature, ie lukewarm. A person will output more heat than that, mainly by breathing out of warmer air.


The heat pumps that are used in Norway heat the air, not a tank of water.
Link


I once lived in a house that had a central heating system that relied on the warm air being distributed to the rooms.

Originally Posted by Chris (Post 36139555)

You may want to try using sources that aren’t 10 years old. I’m heading out shortly so no time, but suffice to say that modern installations need not provide 40*c at the cylinder. They can reach 50*c with an adequately sized cylinder, or 60*c or higher if you add an additional pump inside the house to convert room heat to hot water.

With a heat pump it’s never about whether it can or can’t ‘do’ something. It almost always can. It’s always about the systems installed to manage heat storage, distribution and retention in the home.

The means by which heat is delivered to houses from Norwegian heat pumps is irrelevant to my point - they work, and they continue to work at far lower external temperatures than most of us experience in the UK. The reason people in the UK think they don’t is because our houses are appallingly badly insulated. That’s why warm air ducted heating was only ever a passing fad in the UK, almost invariably replaced by wet radiators after the system became life-expired. If your house is draughty, full of open flues (or badly sealed ones) and with inadequate wall insulation, then the warm air fed through the system is too quickly lost to the outside.

Originally Posted by Mr K (Post 36139517)

New boilers break down, old ones keep going.