Worcester Heatslave 15/19 - little or no hot water if heating's been on

[Debbie_2015]

Hello, has anyone come across the above before?
If we use only the hot water - as we have done up to recently - we have no problems.
But, when we start to use the heating as well as hot water we never seem to get really hot water. We have to wait about a half hour after we've turned the heating off until the water gets really hot again (e.g., for a bath).
I'd be really grateful for any suggestions. We live in a rental property and the odd job man isn't great at fixing things properly.

 

[Burnerman]

Debbie, when you open a hot tap, can you hear a click from the top of the boiler, together with the burner coming on immediately?
John

 

[oilhead]

You need to have the circuitry tested properly. There is a hot water thermostat that takes priority over heating, so your slave tank should always be hot. You may also have a problem with the diverter valve that is very slow to close due to a faulty actuator. This is not a job for an 'odd job man', and you may need to be a bit more forceful with your landlord.