Just to confirm the previous guesses, the heritage trail is still not really happening, so for anyone wishing to visit some or most of the locations, just mark them in your maps in advance. Having said that, the Sheikh Isa Bin Ali House is easy to find. Bahrain overall is best enjoyed with a rental car and there's a parking lot directly behind the property. The present opening hours are rather wonky: 8 a.m. to 2 p.m. on Saturday through Tuesday, 9 a.m. to 6 p.m. on Wednesday and Thursday and closed on Friday so plan your visit accordingly.
The house is a delightful site to visit: it is extensive and even though there isn't any furniture or decoration that remains, I particularly enjoyed the plaster embellishments of walls and gorgeous carved doors - though the best example can be found in the Bahrain National Museum. It has become a popular site with tourists nowadays so prepare not to have it to yourself.