CH boiler replacement, comments/advice please including on Hive and alternatives.

FreeBear

Rollinghome said:

FreeBear said:

Rollinghome said: Or you can use a calculator like https://www.bestheating.com/btu-calculator to make a stab at it, without really knowing their methodology.

I prefer the Stelrad basic heat loss calculator - Punched in the same numbers in both, and got totally different answers. For a 4x4x2.4m bedroom with 2.5m² of uPVC DG Low-E windows, one external 9" solid brick wall, heated room below, and insulated loft above.

Best Heating says 2240BTU (668W), whilst Stelrad says 4130BTU (1210W). Quite a big difference !

A cynic would point out that Stelrad are selling radiators and the bigger they are, the more expensive.

There was a time when central heating installers would give a quotation that guarantees specific temperatures in each room for a specific outside temperature. Such as 21 degrees for lounge, 55 or 60 for bedrooms etc. with outside temperature of 2 degrees say.  The specific requirements for insulation would also be given. For retail installations, that's not done now.

If you are using Fahrenheit, 21°F is almost Siberian. On the other hand, 55-60° Celsius is cooking temperature

21°C (70°F) in a lounge, and 18°C (65°F) in a bedroom are the typical targets used. A -3°C or even -5°C is often used for outside, a bit less if you are up in the Scottish highlands. With a basic heat loss calculator such as the Stelrad one, you can't play with temperatures. For that, you'd need to go with something like Heat Punk.