These tools are built and maintained by one person – a working Building Services and Renewables tutor – not a support team. That means I read every message myself, but replies won’t be instant. Please bear with me.
If a calculation looks wrong, a tool misbehaves, or you’ve got an idea to improve things, I want to hear about it.
Email me using the button below. Your app build version is added to the email automatically. To help me act on it quickly, please add the device and browser you’re using, and what happened.
Email support© 2026 Stephen J. Denney (app design and original content). Incorporates material from Gas Installation Technology, 3rd Edition (Burcham, Denney, Treloar), © John Wiley & Sons, Ltd. For use by Gas Safe registered engineers. Not for public distribution.
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