Thanks for your response :)
The boiler is only 1.5 years old and I didn't take up the extra year warranty.
Is the diverter valve part of the APS unit ?
Hi,
I've just returned from a 2 week holiday and my Vaillant TurboMax Combination boiler is not heating water. The status code is sometimes S.33 (Check Air/Flue System) but other times when I turn the hot water tap the boiler kicks on but the temp doesn't increase – it stays around 20C...