Cool domestic hot water

[whistler]

Boiler is vaillant 824 turbo max.

Since the very cold spell of last few days, DHW has been intermittently warm, but not hot the diagnostic codes are all as they should be, indicating diverter valve is operating ok.

Could this just be due to the very cold incoming water supply, or diverter valve not functioning correctly? By coincidence I have my engineer coming tomorrow for the boilers annual service, so would like to see if his diagnosis agrees with the experts here.

 

[Bod ...]

Boiler is vaillant 824 turbo max.

Since the very cold spell of last few days, DHW has been intermittently warm, but not hot the diagnostic codes are all as they should be, indicating diverter valve is operating ok.

Could this just be due to the very cold incoming water supply, or diverter valve not functioning correctly? By coincidence I have my engineer coming tomorrow for the boilers annual service, so would like to see if his diagnosis agrees with the experts here.

Tell him about the lack of hot water and just see what he comes up, without letting him know what you have read.

It might just be an out scaled up boiler.