after holiday 2 appliances dead, can i claim on contents?

Things to consider:

1) Evidence that there was lightning during the dates in question (try looking online - if you can find a legitimate source that suggests there was, your insurers need to disprove it... they have access to weather records).

2) A report on why the appliances failed. An appliance engineer should be able to help with this. There should be evidence internally of something being fryed.

3) An explanation as to why these were the only two items to be affected/fail. If other items were on the same ring or in the same location, there must be a reason they survived and these didn't?

The supply doesn't seem to be the issue when not being used, but there is clearly an issue when the appliances try and run. I assume they are taking more than the constant supply when running, so it is worth looking at the electrics as well.

As mentiong before, you need to prove a valid loss under the policy. Failure of appliances isn't generally covered. It is odd that two have the same problem, unless they are in the same area and there is a bug on the electrics.

It isn't up to your Insurer to prove your claim for you, so you're going to have to get the faults on them diagnosed before anything else happens. Instead of asking people to come and look to confirm X happened, ask an engineer to take a look and explain why the items have failed. If the reason for the failure could be due to lightening, then look at if there was any whilst you were away and look for any other evidence. Also, get your electrics checked out just to be safe.

Only you can answer how badly you need the insurance payout for the Siemens tumble dryer. In this circumstances it's perfectly normal from the insurer to demand proof of insurance event, as usually appliances failing isn't covered by content insurance.

Whether the insurer will reimburse you for the £45 in an event of a payout is anybody's guess, ask them.

In any case if this has happened once I would be getting an electrician to potentially find out why it happened. If it wasn't an external factor such a lightning strike etc. there might still be a latent fault in your wiring. Who knows when it might cause issues again.