I wonder if that might actually be a medium term solution - plumber's due to come service my boiler soon, so he might be able to rig something up under the sink so that I can connect a hose/karcher that way...
Yes, I was thinking could you put an outside tap in under the sink or somewhere hidden away, its a relatively straightforward job if you have plastic pipes, only thing plumber might be wary of is if it leaks its not above a drainage solution.
I wonder if that might actually be a medium term solution - plumber's due to come service my boiler soon, so he might be able to rig something up under the sink so that I can connect a hose/karcher that way...
@Sam_w thanks - looks from this video that a big bucket would probably work for this model https://youtu.be/yhGlOq_x0f4?t=225