Arguing with Vaillant about boiler problem!

[scatmanjohn]

He has been described as one of the top ten combi engineers in the country!

and

That's only nine, where's the other one gone.

.........

 

[Onetap]

You have totally misunderstood how the boiler works. There are two HEs!

The Primary heat exchanger transfers heat from the hot flue gases to the primary water, which is pumped to either the radiators or the secondary heat exchanger depending on the position of the diverter valve.

The Secondary heat exchanger transfers heet from the primary water to the secondary water, the hot water supply that comes out of your taps.