I have a radiator in my tiny bathroom that is installed \\\"on its side\\\", with pipework entering at top and exiting at bottom. Pipes come from ceiling. This is because the wall space is very narrow. It works fine. Bathroom is ground floor - combi boiler is on first floor. I want to replace it with a narrow heated towel rail. Is it OK to leave pipework as is or should I reroute so that the plumbing is at the bottom?