Saunier duval hot water problem

[handlil]

When I run a bath, initially, I get hot water, then it goes cold. The boiler continues to look as if it is heating. Sometimes the hot water comes back and then again disappears and it runs cold. In have no problem with the hot water in the kitchen or in the shower - only when I try to run a hot bath.

 

[SimonG]

Reduce the flow through the bath hot tap.

 

[stevetheplumber]

tap is running faster than the boiler can deliver try running the tap slower

 

[handlil]

I tried running the tap slower but the problem persists.

 

[Rickster123]

Time to get someone in to have a look then I'm afraid.