So, fitted approx 4 new neta tec's this year. As I liked the duo tec I thought I'd carry on the tradition and try them, I've read posts and imputed my take on them... overall, I like them. But now I've just had a call from second gas valve failure,( which was fitted approx 3 months ago) With very little chance of having an engineer come out tomorrow or Saturday, I can say don't bother! At least until they sort their mess out. How about telling your loyal customer that on your last job before the holidays. Nice!