Temperature control

Hi,

I am having problems with a package heat pump system. It is in an office and the occupants are complaining of poor temperature control, basically, its either too hot or too cold, and the temperature changes dramatically throughout the day.

Every time I visit the office, the temperature is either fine, or the controls have been altered.

The unit is a Lennox and was installed in 1995ish. The controller is a DSL700LX. The air conditioning service guys said that its been installed well, with good ductwork and they also think the controller works fine.

I did ask for a price to change the controller to something more modern, but was told that the unit should only be used with the DSL700LX and they quoted £600 to replace it.

One last thing, there is a dip switch to change it between single stage and multi stage, what position should this be in?

We did have the controls locked with the lock switch, and during that time, they still complained about the massive temperature swings.

I'm a bit stuck as to what to do next, I'm not an engineer, just the one that gets all the hassle!


Thanks in advance