Need to find Affordable Home Repair Businesses

The best advice I can give is to ask your neighbors who they use.  Everything depends on where you live.  Checking Anigie’s List is another option.  

Local Home Repair Assistance Programs may be a good option to start with. Many cities may have free or low-cost help for seniors, or homeowners with a limited income.  Nonprofits such as Rebuilding Together support clients make "critical repairs," or repairs needed for safety and basic function, which includes plumbing repairs. 

If you are hiring a private plumber, HomeAdvisor and Angi are both good resources for an overview of reviews and getting a few quotes from licensed plumbers.  As always, make sure they are insured, and have a clear estimate in writing for the work to be done before the work gets started.

In conclusion, checking local aid programs, verifying credentials, and getting a few quotes are a great way to find reliable help affordably.

Angie List is most likely your best bet. Also might check with your BBB to see if they have a list.