Neil Ashdown MAFDI

This self-closer is not suitable for a fire resistant door. Read the section on door self-closing devices at this document for more information: https://www.firecode.org.uk/

From what you have said here, it would seem the door was in poor condition. A fire door should completely and reliably self-close without having to be pushed, so the fact that it failed to do so would suggest that the door was in poor condition.

If the doors need to be fire resisting doors but are of a non-standard size or shape, then you will need to buy custom made fire doors and door frames.

There is no mandatory requirement in terms of the Regulatory Reform (Fire Safety) Order 2005 for existing emergency exit / panic escape hardware to be CE or UKCA marked. However, Article 17 of the Order requires that they are maintained in good repair and in efficient working order.

Nominal fire doors can only ever be existing doors already installed in a building - one would never install a nominal fire door. Any new fire door that you purchase to install at the holiday property will have documentary evidence of fire performance. Therefore the door must be installed in accordance with the manufacturers certification. The frames and handles may be reused provided that they comply with the specification in the manufacturers certification, including where the door frame reverse face meets the surrounding wall construction.

Misalignment of the door leaf and door frame is a common issue. In terms of requirement of the installation to comply with product certification the door leaf must not stand proud of the door frame or if this is permitted there will be a very tight allowance, typically 1mm. As far as the door leaf being "off" the rebate stop, I have not yet encountered a limit for this issue and recommend where the stop is the planted type that it be moved to compensate for any twist in the door. For a frame with a rebate machined from the solid this would not be possible of course. To be correct, one should always check with the particular door manufacturer to see what is permitted in terms of tolerance for the door leaf to stop dimension.

So long as the specification of the existing door frame meets the requirements for the new door leaf, then yes. So you need to obtain the product data sheet for the new leaf and check that the existing frame meets the requirements therein.

Or if you do want to persevere with a timber door, try Strebord or Strecore here https://falcon-timber.com/downloads/

One more that could be worth a try. This guy knows his stuff https://www.solarwindows.co.uk/team/3/john-lewis

Be sure to check the technical manual for the timber fire door core or installation data sheet for a timber fire door leaf. That document will advise which ironmongery is permitted.

If that won't work because the door leaf closing edge is eased at the corner, you could use these instead:

Use flat intumescent strips (fire-only) but with batwing seals to deal with restricted smoke spread.

You could ask these people https://www.permadoor.co.uk/contact-us/

Double swing action door?

https://www.firedoorscomplete.com/news/nominal-fire-doors-notional-fire-doors-upgrading-fire-doors The revised version of BS 8214 is due out soon, it might have a different view! Its open for comment at https://standardsdevelopment.bsigroup.com/Unauthenticated