"My friends Joe and Penny in Coventry are now without their heating, their Netaheat has failed totally. I fitted it in June 1975!
It is the original Netaheat, now known as the Mk1, the 10-16 model. What is required is the mercury vapour valve. Here is a view from the service manual of the gas train : you can see the gas coming from the main gas cock, to the solonoid valve, then the regulator (pressure) and then the mercury vapour valve, two sizes shown (10-16 and 16-22). You can also see the phial from the mercury valve at the top of the sheet, in its location in the pilot mounting bracket.
The 10-16 valve is tapped ¼"BSP, the 16-22 valve being larger and tapped ½"BSP. I'm sure if only the larger valve was to be had I can bush it down to ¼", alter the pipework slightly, etc, no prob.
So you see this valve is a gas carrying part, unlike the mercury vapour switch on the Mk2, which is simply an electrical device operated by the vapourising mercury. And plugs into the gas valve (White Rogers composite control). Unlike yours, which satisfies itself your pilot is burning by electronic means.
I also give you a high res close up photo of the valve in situ showing its markings and date of manufacture."
If anyone can help me help my plumber I would be very, very grateful!
