We're in the process of changing a bathroom and moved the radiator. All the pipework is done and floors are currently being laid. The radiator is a dual fuel towel radiator with one angled and one straight valve. We need to determine which pipe is the inflow to the radiator and which pipe is the outflow (unfortunately these pipes were not marked when the old radiator was removed) to cut the floor boards. Furthermore, the boiler is not working and a new boiler would be installed in a few weeks. To install the radiator and see whether it works is therefore not possible. Is there a way to determine which pipe is the inflow and which is the outflow without installing the radiator is there is currently no working boiler?