I have a Honeywell RTH 230B thermostat when the batteries need to be changed it will flash off and on it was flashing so my Mom took out the batteries and replaced them 6 different times. Now the thermostat will not come back on. Is there anything that I can do maybe some kind of by-pass to get around the batteries or even someone who might be able to tell what could have caused the problem in the first place? Thank you I look forward to your suggestion and answers.

https://customer.honeywell.com/resources/techlit/TechLitDocuments/69-0000s/69-1800.pdf

What do you mean Now the thermostat will not come back on. Is the display BLANK? Did you reset the time and date? Review the battery replacement section and section 5-1. Let me know what happened and I will assume the batteries are in correctly (Polarity+ or -)

Also review this link

https://www.hunker.com/13415780/how-to-troubleshoot-rth230b-honeywell-thermostats OR Honeywell RTH230B Thermostat Troubleshooting | Troubleshooting Manuals (http://www.troubleshootingmanuals.com/thermostat/honeywell-rth230b-thermostat-troubleshooting/)

Get back to me about that display screen, BLANK, or NOT? Was it blank every time you changed batteries?