only you can decide that Ric, depends on what you're happy with.
Do you want a quick sale?
If so, accept the 220, alternatively suggest to lawyer that the offer is too low and closer to 230 would be better.
It is about 7% below asking price, which is about average for the country. It depends whether 237K or 250K was the fairer asking price. If you thought 250K was reasonable I would hold on a bit.
I know you've asked about this sale before and as others have said wait if you're not in a hurry but with one proviso - have estate agents told you 237 is a fair price? If it's overpriced it's not going to sell anyway until the market inflates it to that price so you could be waiting a long time.