Went to a no heat call. Found that the thermocouple and the thermostat were both bad. I did not want to do the repair due to the age of the system Steve will need to come out here and quote them for a new system. Customer needed heat for tonight due to living conditions. So I went forward with the repair customer does have heat I cannot guarantee for how long system is 40 years old. Put in a Honeywell T4 thermostat. System is running properly at this point but will need to be replaced as soon as possible for a reliable source of heat.