The heat exchange failed on my Camray 90 oil boiler with an internal failure allowing mains water to pressurise the heating system to 3bar and slowly passing through the relief valve.
Whilst this was not a problem that required attention immediately, this quality item was sourced and received within 2 days. The item was supplied with the correct washers and was an exact fit, with replacement and testing taking around an hour.
Very happy with this product.