You do realise it's unlawful to work on a domestic gas appliance if you aren't Gas Safe certified?
Manual here:
http://www.acwilgar.co.uk/Boiler-Manual-PDF/Baxi/BAXI%20WENTWORTH%20PCF%20DELUXE%20GCNo.32-075-16A.pdf
And
https://www.manualslib.com/manual/883011/Baxi-Wentworth-Deluxe.html
Having said that, most spares seem to be discontinued.
Typical resource:
https://www.dhsspares.co.uk/category/gas-fire-spares-uk/appliance/baxi-wentworth-deluxe-bax352
More stuff here:
https://www.diynot.com/diy/threads/baxi-wentworth-gas-fire-gc-32-075-34.201792/
Ggfd, October 2024
