AC Issue

[Stephen E.]

I have a townhouse with a 20+ year old air conditioner and furnace. My tenant reported that if she set the thermostat at 75F the system would cycle on and off as is normal. However, when she set the thermostat at 74F it would run constantly and not shut off.

I have spoken to two HVAC technicians and they have both suggested that this may be normal operation in that each AC system is rated for a given capacity of cooling, and if the rate of heat entering the unit is greater than the capacity of the system it will run constantly. The tenant is not satisfied with this, although she talked with a HVAC technician from the company I deal with today and in his conversation with her in which he questioned her about the operation of the HVAC he came to the view that the system was likely operating normally.

Notwithstanding this we are paying for a service call. Landlord Tenant laws in Ontario are such that you have to document some response to every tenant maintenance complaint. So we are sending a technician out to inspect. 

My question is, what do BPers make of the advice received from HVAC guys to date? What would you do?