Duel Fuel System

[mike350]

I have A duel fuel system - the heat pump is the primary and the oil is the back-up. Is this the order that is should be or is the oil supposed to be the primary heat and the heat pump as backup - also how do i find out what temperature the heat pump cut off (It never cuts off, it sounds like it goes into defrost mode when the oil furnace goes on) any help/explanation would be great as i have bought a house with this system and just trying to figure out how it works

Thanks

Mike

[Infohunter88]

Hey Mike, Heat pump always is your 1st stage, but the heat pump must shut off completely when your oil furnace kicks on, If you do not have an stat that has a built in fossel fuel kit than you will have to get one or put a fossel fuil kit on It will be best to have a t stat like a Vision Pro 8000 series an it will do it all for you , Just read ALL the dirrections first if you are not familiar with that stat.

[glennac]

Are you a homeowner? It so it sounds like you need to call up someone in charge of you company that installed your unit and get them out there and fix the problem. Infohunter is correct but its not your responsiblity to correct a screw up by a installer.

[mike350]

The fan is stopped but the compressor is still running I guess, Maybe it is in the defrost mode - I know for a fact that the fan is not running - is that OK?
the thermostat is a Honeywell 8624d - It seem like it is working.

I am a homeowner and just bought the house with the existing hvac - I is working - i just do not want to blow up the heat pump !!

Also is it ok to set the thermostat for auto mode. The current owner did not have it set up for it. Do you have to do anything different to the heat pump or the oil furnace to enable that function?

[glennac]

The auto mode is normally used in the winter and the on mode in the summer. "Auto" has the furnance fan blowing only when the heat or cooling is on. "On" has the fan running continuously. I would use the auto in the winter unless you have one unit serving a two story and want to maintan a more uniform temperature between up and downstairs. You need to call a HVAC company or a recomended service tech who has experience in dual fuel and he can fix your problems.