A/C Thermostat Malfunctioning

I have a two storey home with two thermostats(Honeywell) controlling the upstairs and downstairs independently of eachother. The cooling system is Lennox. Lately the downstairs airconditioning seems to shut off when the upstairs is turned on and sometimes completely stops working. Any suggestion on what needs to be done would be greatly appreciated! Thanks! Michelle
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.