Can you switch on hot water while radiators are drained?

[Apnomis]

Question as subject, I'm waiting on a part which won't be here until tomorrow but I really want to turn the hot water on if I can? The radiators are drained and I've tied up the ball in the expansion tank. It is an old two valve boiler as pictured, if I only turn on the hot water will it damage the boiler? Should I manually shut off any of the valves before doing this? Or is it better to keep the whole system off?

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[stem]

If you have drained the radiators and the tank feeding the boiler is empty, then the boiler will also be empty. You must not switch the boiler on under any circumstances.

However, your hot water cylinder will be filled from a separate feed and expansion tank, which assuming that it is still full, and that there is water flowing freely out of your hot hot taps, then you can use the immersion heater fitted to the hot water cylinder to heat your hot water safely.

It is an old two valve boiler as pictured

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• stem
• 24 Feb 2015
• 1

BTW, that picture is not a boiler. That is a hot water cylinder.

 

[Apnomis]

Thanks I'll use that