Bath only has fully hot water when central heating is on
I live in a flat with a communal heating system and an MHS boiler in my flat. The kitchen and bathroom taps have hot water (though in the case of the kitchen tap it can take a little while to heat up but after that it will stay on. Similarly the shower also has constant hot water. The bath however has hot water but only for a few minutes then it goes cold. The hot water will then come back after 20 minutes but again only for a few minutes however its constant when the central heating is on.
Advice from 1 local tradesperson
It sounds like the flow of water on the bath is to great for the boiler.
Try running the tap slower, about half of fully open and see if this remedies the issue
