Looks like apple or crab apple to me, but it could be one of a few different fruit trees for all I know.

It is definitely not an apple or crab...

It is also thorny.

I think you're right.... looked up quince.. sure looks like that.

Have a look at this

https://www.bing.com/images/search?q=toyo-nishiki&qpvt=toyo+nishiki&FORM=IGRE

Definitely Chaenomeles.

Thanks... I inherited the bush... the thing I don't like about it is the thorns. We walk past it along our walkway to the pool and I have to sheer it back or else we'll get pricked.. seems very vigorous. I sheer it back and it responds with more growth.. doesn't matter when I do it.

Head back the current season's growth in summer. If you really need it to be flat against the house - maybe that was the idea with the original planting - and there are enough branches back there already cut the branches in front of this back layer off during winter.

And then going forward from that point prune each summer to maintain the new or restored shape, cutting off attempts to regain the previous structure at the ground. And shortening shoots coming from the front of the retained section that point away from the wall.

If instead the base of the shrub is located well out away from the wall then maybe you'll just have to remove it. The fundamental issue being the shrub is too large growing a kind for that planting site.