Hot bath water

[lobsters15]

I spoke to the technical department at Baxi.

Your equation is quite unhelpful and really makes little sense. It would be sensible to specify units. Please reply with some worked arithmetic as I cannot make any sense of it.

 

[bengasman]

The formula I gave you is really rather simple; straight forward equation with 3 variables.

As been posted above, the boiler heats a certain amount of water a certain number of degrees, doubling the required temperature halves the number or litres per minute. The more kW's in the boiler, the more litres per minute.
It's completely linear, so take the numbers from the book, and divide or multiply as you please.

 

[lobsters15]

Many thanks.

I thought the relationship had to be linear although the technical people I spoke to at Baxi, Worcester Bosch and Viessmann's said otherwise. They said the water would get hotter by reducing flow rate but limitations set by the boiler would stop a linear relationship.

If the relationship is as you say then getting a 42kW Worcester Bosch or a 40kW Baxi combi and reducing the flow rate should produce the hot water my wife requires for her bath.