Electric UFH Is My Bathroom Subfloor Good Enough? - Tile Advice

[J-S-Q]

I am DIY refurbing a bathroom in my house and would be grateful for some advice...

The subfloor is T&G chipboard, nailed onto joists. It was previously tiled and had UFH but I have now stripped this. My plan is to install Warmup DCM-Pro, with 100mm Warmup insulation boards and then tile on top.

There is a certain amount of tile adhesive residue left from the old installation so the surface is a little uneven. I guess it has some bumps of 2-3mm. There are also a few small punctures in the flooring (see photos). What is my best way forward? Should I:

a) Crack on and glue down the insulation boards.
a) Repair the holes somehow and possibly apply self-leveling compound.

b) Rip up the chipboard and replace with plywood.
c) Something else?

Thanks!
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[Wayne Brown]

The job will only be as good as the prep I would overboard with hardi backer first screwed down and sealed as their spec you then has a new stable surface to work off others may disagree . Kop