Is it worth putting electricity and water contracts on hold while in the UK?

You'd need to sign a contract with fixed dates and once that contract terminates, you'd have to pay again for re-connection for your next contract dates. It can take a couple of weeks for the electricity to be re-connected once you apply for it and that's on the off-chance that the electricity company hasn't removed the meter from the property. For the small amount that you'd be saving in electricity costs while you are away if you're not using any appliances, I wouldn't think that it would be worth the hassle! As far as the water goes, having empty pipes can result in damage to the pipes and easy access to all sorts of nasty smells and creepy-crawlies.

I’d completely agree with this. The reconnection fees are quite high, a huge faff and not always reliable or quick. 

In addition to the other responses, for the electricity, if you leave it connected, you will pay the 'capacity invoiced' part of the bill, which, depending on your potencia, is probably around €20 per month, plus meter rental at approx. €1 per month; plus the reduced IVA @ 10% on those, so you could probably allow €23 per month for those - which versus the inconvenience and cost of disconnecting & re-connecting is probably worthwhile swallowing.

Also, if you are currently on a fixed tariff contract, you would lose that and, given the current worldwide increases in energy prices, you would probably re-contract in 6 months time at a considerably higher rate.

Agree with the previous replies. If you're looking to save money, an easier way might be to switch electricity supplier - if possible. I found the standing charges with Iberdrola expensive, so I switched to Siesta. Its standing charges are about half those of Iberdrola. I don't know if this would be an option where you are (?). I should also say that I have no connection with Siesta, or any other supplier of electricity - just based on personal experience.