If I drain a hot water system - for example to repair a hot downstairs tap on an indirect system - is there any danger of the boiler or immersion heater causing damage to an empty hot water storage cylinder?
If you were to drain the cylinder completely, and then turn the immersion or boiler on - then yes you could damage the immersion heater or the cylinder.
If you only turn off the cold supply to the cylinder and open the hot tap, to drain the hot water pipes, then you're not draining the cylinder. The cylinder will still be full and therefore no damage will occur.
DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!