Pressure drop if heating and hot water on

[LeeUK]

Asking for a friend.

Oil heating - when the heating is on (morning) and someone runs a bath or has a shower the pressure drops on the boiler and cuts out, the boiler then needs to be topped up (pressure) before it kicks in again.
I thought the water pressure (flow) to the shower/bath needs to be lowered to allow them both to run simultaneously, am not familiar with their setup so asking for info here.

Any ideas appreciated.

 

[PrenticeBoyofDerry]

What make/model boiler is it?

 

[LeeUK]

yeah, might help, no idea at present.

 

[dcawkwell]

Sounds like you have a leak in the plate heat exchanger and low water pressure in the house.