Thanks for replying – it’s a capillary type with bulb. Having said that it’s all a bit moot now as, coincidentally enough, we took delivery of a new fridge/freezer today. I emailed the shop about which thermostat I needed and mentioned I hadn’t had a reply to my thread but that it didn’t matter as if it wasn’t the thermostat then it was beyond me and not worth the cost to get someone in. The person who replied looked at the thread and in no uncertain terms said it was the compressor. For c£25 I would have tried the thermostat if the answer was possibly or probably but that wasn’t the case and whilst we’ll never know now we’ve moved on. And ‘fairly old’ is an understatement. On taking down the carcass (the Neff was built in) the supplier label had a date of 1981 and I’ve no reason to believe the fridge didn’t come with it. So it was 40 years old (and I strongly suspect hadn’t been working properly since before we moved in nine years ago) – indeed an antique, as it was referred to, and no doubt time for us to enter the 21st century!