Heater Suggestion for Spa only

[CarrolltonTXPool]

I currently have a broken and unrepairable Lara Lite 2 heater (400,000 BTU's) We are selling the house and the buyers want the heater fixed. Its around $2950 for the only quote i have so far to remove old, install new master temp 400 heater. If they were interested in replacing the old heater with one that was mainly for heating the spa only, what size would be acceptable? Here are two pics for scale of the size of the spa. Is this something that is done? Any help would be great as we have until tomorrow night and I want to do what it takes to get this done.

The pool is plumbed so it is able to switch to just the hot tub in case that matters.

 

[ps0303]

You can easily heat that spa very nicely with a 250,000 BTU unit. Personally I would put in a Raypak 266,000 BTU, they don't make a 250K, as it will line up very nicely and quick. Should save you $500-$600 going with the smaller size unit. It would also heat the pool as well but no real fast.