Hi, I’ve recently bought a property that had a wood burner installed. I’ve removed the stove to make alterations to the hearth and have noticed the flue looks like it’s only a single walled 6” liner. I’m wondering how I can find out if this is an adequate liner that’s fit for purpose or not. The previous owner doesn’t have the paperwork and I’ve checked with hetas and it’s not been registered with them either. He had some building work done in 2014 and bought the property in 2012 and there was definitely no stove installed prior to his purchase. Any advice on how I can check if it’s ok or not is greatly appreciated. Thanks.